Answer:
2.01
Explanation:
First, we need to find the centripetal acceleration.
We're given that the merry go round rotates 1 revolution in 2.09 seconds. Converting to rpm, we know that it rotates 30 revolution per minute
Now this speed gotten in rpm will be converted to m/s, to ease the calculation
30 rpm = πdN/60 m/s
30 rpm = (3.142 * 4 * 30)/60
30 rpm = 377.04/60
30 rpm = 6.284 m/s
a(c) = v²/r
a(c) = 6.284²/2
a(c) = 39.49 / 2
a(c) = 19.74 m/s²
F = ma
F = 50 * 19.74
F = 987 N
Also, Normal Force, F(n) =
F(n) = mg
F(n) = 50 * 9.81
F(n) = 490.5
We then use this to find the coefficient of static friction, μ
μ = F/F(n)
μ = 987 / 490.5
μ = 2.01
a rock falls for 4 seconds. How far did it fall
Answer:
d = 80 m
Explanation:
It is given that,
A rock falls for 4 seconds.
We need to find how far did it fall.
let it cover d distance.
Using equation of motion to find it :
[tex]d=ut+\dfrac{1}{2}at^2[/tex]
Here, u = 0 (at rest initially)
a = g
[tex]d=\dfrac{1}{2}gt^2\\\\d=\dfrac{1}{2}\times 10\times 4^2\\\\d=80\ m[/tex]
It will fall at a distance of 80 m.
The distance between the object and its image formed by a plane mirror appears to be 24 cm. What is the distance between the mirror and the object?
Answer:
in a plane mirror distance of object from mirror is equal to distance of image
so it will be 24 ÷ 2 = 12 cm
1) A rock is thrown downward from the top of a 40.0-m-tall tower with an initial speed of 12 m/s. Assuming
negligible air resistance, what is the speed of the rock just before hitting the ground?
Answer:
By using [tex]v^{2}_{f} = v^{2}_{i} + 2a\Delta y[/tex], with [tex]v_{i} = -12m/s[/tex] and [tex]\Delta y = -40m[/tex]:
[tex]v^{2}_{f} = v^{2}_{i} + 2a/Delta y[/tex]
[tex]v^{2} = (-12m/s)^{2} + 2(-9.80m/s^{2})(-40m)[/tex]
[tex]v = -30m/s[/tex]
Explanation:
Hope this helped!
A rock is thrown downward from the top of a 40 m tall tower, with The speed of the rock just before hitting the ground will be equal to -30 m/s.
What is Friction?Friction is the resistance to a thing moving or rolling over another solid object. Although frictional forces can be advantageous, such as the traction required to walk while slipping, they also provide a significant amount of resistance to motion. In order to overcome frictional resistance in the moving parts, about 20% of an automobile's engine power is used.
The forces of attraction, also referred to as adhesion, between the contact zones of the surface, which are always minutely uneven, seem to be the main contributor to friction between metals.
From the given information in the question,
v²(f) = v²(i) + 2aΔy
v² = (-12 m/s)² + 2(-9.8)(-40)
v = -30 m/s.
Therefore, the velocity of the rock is -30 m/s.
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it is difficult to smooth floor why
Complete question is:
It's is difficult to walk on a wet floor than a smooth floor. Why?
Answer:
Because friction on wet floor is far lesser than on a smooth floor
Explanation:
On wet surfaces, the friction is far lesser than on smooth surfaces and thus the grip between the bottom of your shoes/feet and the ground is very very small and as such walking on the wet surface becomes more difficult. Whereas on Smooth surfaces, there is plenty of friction and as a result, there is enough grip between the bottom of your shoes/feet and the ground thereby making walking far easier.
What is albedo? What on Earth has high albedo?
Answer:
The fraction of incident light or radiation reflected by a surface or body, commonly expressed as a percentage.
2.
biology The whitish inner portion of the rind of citrus fruits that is a source of pectin, commonly referred to as the pith.
Explanation:
A 15 N force is applied to a 12 kg box for 6 s. The box is initially at rest. What is the speed of the box at the end of the 6 s interval
Answer:
The speed of the box at the end of the 6 s interval is 7.5 m/s.
Explanation:
Given;
magnitude of the force, f = 15 N
mass of the box, m = 12 kg
initial velocity of the box, u = 0
time of the box motion, t = 6s
The applied force on the box is given by Newton's second law of motion;
f = ma
where;
a is the acceleration of the box
a = f / m
a = (15) / (12)
a = 1.25 m/s²
The final velocity of the box is calculated as;
v = u + at
v = 0 + (1.25 x 6)
v = 7.5 m/s.
Therefore, the speed of the box at the end of the 6 s interval is 7.5 m/s.
Electrical equipment in an office takes a current of 13 A from a 240 V supply.
Estimate the cost per week of electricity if the equipment is used for 30 hours each
week and 1 kWh of energy costs Rm0.50
Answer:
The cost per week of electricity is Rm 46.8
Explanation:
Electrical Power and Energy
The electrical power consumed by an appliance connected to a voltage V and carrying a current I is given by:
P = V.I
The energy consumed by an electrical appliance of power P during a time t is:
E = P.t
The electrical equipment in an office takes I=13 A when connected to a V=240 V supply.
The power consumed is:
P = 240 V * 13 A
P = 3,120 Watt
Converting to Kilowatt:
P = 3,120/1,000 KW
P = 3,12 KW
If the equipment is used t=30 hours each week, the energy is:
E = 3.12 KW * 30 h
E = 93.6 KWh
Since the cost of each KWh is Rm 0.50, the weekly cost of electricity is:
C = 93.6 * 0.50 = 46.8
The cost per week of electricity is Rm 46.8
Which statement describes the factors that affect the force of friction? Question 2 options: Friction is always the same no matter what Friction increases as the normal force (weight) increases, and also depends on the surface Friction is greater when objects are barely touching Friction is greater on slippery surfaces
Answer:
(b) Friction increases as the normal force (weight) increases, and also depends on the surface
Explanation:
The coefficient of friction relates the normal force between surfaces to the friction force opposing motion. The coefficient depends on the surface.
The appropriate choice is ...
Friction increases as the normal force (weight) increases, and also depends on the surface
A mixture contains salt, sand, pebbles, and grass. Which part of this mixture is soluble in water?
Grass
Pebbles
Salt
Sand
Answer:
hey!
the answer is
salt
Explanation:
this is due to sand, grass and pebbles are not soluble (they do not dissolve in water)
pls put brainliest
If The density of this stainless steel is7.85 g/cm3,specific heatis 0.5 J/g.K, melting pointis 1673K, heat of fusion s0.260J/kg. How much energy is required to re-melt this tube completely from room temperature
Answer:
[tex]\Delta H=687.4 J[/tex]
Explanation:
Hello!
In this case, for this melting process, we can identify two sub-processes in order to take the stainless steel from solid to liquid:
1. Heat up from 298.15 K to 1673 K.
2. Undergo the phase transition.
Both process have an associated enthalpy as shown below:
[tex]\Delta H_1=1g*0.5\frac{J}{g*K} (1673K-298.15K)=687.4J[/tex]
[tex]\Delta H_2=0.001kg*\frac{0.260J}{kg} =0.00026J[/tex]
Therefore, the required heat is:
[tex]\Delta H=\Delta H_1+\Delta H_2\\\\\Delta H=687.4J+0.00026J\\\\\Delta H=687.4J[/tex]
Notice the problem is not providing neither the mass or volume, that is why we assumed the mass is 1 g; however, it can be changed to the mass you are given.
Best regards!
which law of thermodynamics would be violated if heat were to spontaneously flow between two abject which are in thermal equilibrium?
Answer:
The law zero of thermodynamics.
Explanation:
The law zero of thermodynamics, which tells us that heat flows from a body at a higher temperature to another body with lower temperature, when the heat transfer is zero, it is said that the two bodies are in thermal equilibrium, their temperatures are equal
using the forces applied to the system, determine the mechanical advantage of this pulley
A) 0.5
B) 2.0
C) 50
D) 100
Answer: the answer is B. 2.0
Explanation:
A 40-kg person is climbing 3 m up a flight of stairs in 6 seconds. How much work did they do climbing the stairs? (acceleration due to gravity = 10 m/sec2)
Answer:
1200J
Explanation:
W.D=mass×accelerarion due to gravity×distance
W.D=40kg×10m/s²×3m
W.D=1200kgm²/s²
W.D=1200J
A 40 kg person is climbing 3 m up a flight of stairs in 6 seconds, then the work done by the person to climb the stairs is 1200 J.
What is Work done?When we apply a force called "F" to a block, the body moves with an acceleration or, additionally, its speed changes depending on the force's direction. The system's kinetic energy changes depending on whether the speed increases or decreases.
Energy must be transformed into another form because, as far as we are aware, it cannot be created or destroyed. In this view, it is referred to as work completed.
[tex]Work\ done = Force*Distance[/tex]
and Force = mg
Substitute all the values in the above formula,
W.D = 40 kg × 10 m/s² × 3 m
W.D = 1200 kg m²/s² or,
W.D = 1200 J
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1. Answer the question below. Use the rubric in the materials for help if needed.
Devon drove 50 miles west and then drove 15 miles north. Determine Devon's displacement. Show your work.
I need help
Answer:
d = 52.20 miles
Explanation:
Given that,
Devon drove 50 miles west and then drove 15 miles north.
We need to find Devon's displacement. Let it is d. It can be calculated as follows :
[tex]d=\sqrt{50^2+15^2} \\\\=52.20\ \text{miles}[/tex]
Hence, Devon's displacement is 52.20 miles.
A rod is made of three segments of equal length with different masses. The total mass of the rod is 6m. Will the moment of inertia of the rod be (i) greater about the left end, (ii) greater about the right end, or (iii) the same about both ends
Answer: (iii) the same about both ends
Explanation:
The moment of inertia is the sum of the square of the distance from the axis of massage and rotation of each length of the rod. The moment of inertia can be expressed as I = imiri2. The connection of the rod is the product of the moment length and distance (square), so it is the same at both ends.
The moment of inertia depends on the distribution of mass and the square of the distance from the axis.
The moment of inertia of the rod is the same about both ends. Hence, option (iii) is correct.
What is the moment of inertia?The degree measure of the resistance of an object towards an angular acceleration about the given axis is known as the moment of inertia of an object.
Given data -
The total mass of rod is, M = 6m.
The moment of inertia is the sum of the square of the distance from the axis of massage and rotation of each length of the rod. The mathematical expression is given as,
[tex]I = M \times r^{2}[/tex]
Since the connection of the rod is the product of the moment length and distance (square), so it is the same at both ends.
Thus, we can conclude that the moment of inertia of the rod is the same about both the ends.
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8
9
TIME REMAINING 10:34
Which statement describes an atomic nucleſus?
An atomic nucleus is negatively charged.
An atomic nucleus has no electrical charge.
An atomic nucleus consists of mostly empty space.
An atomic nucleus contains most of the atom's mass,
An atomic nucleus . . .
-- contains all of the atom's positive charge
-- contains almost all of the atom's mass
-- contains none of the atom's negative charge.
Answer:
An atomic nucleus . . .
-- contains all of the atom's positive charge
-- contains almost all of the atom's mass
-- contains none of the atom's negative charge.
Explanation:
yaaaaaa what the person on top said
A jet aircraft is traveling at 219 m/s in horizontal flight. The engine takes in air at a rate of 77.9 kg/s and burns fuel at a rate of 4.19 kg/s. The exhaust gases are ejected at 934 m/s relative to the aircraft. Find the thrust of the jet engine. Answer in units of N. 019 (part 2 of 2) 10.0 points Find the delivered power. Answer in units of W
Answer: thrust [tex]-85905.24N[/tex]
delivered power [tex]= -18813247.56W[/tex]
Explanation:
given data:
horizontal speed = 219 m/s
rate of air intake = 77.9 kg/s
fuel combustion rate = 4.19 kg/s.
exhaust gases ejected = 934 m/s
solutuon:
Thrust of the engine
[tex]Fth = Ve * ( Mf - Ma ) - Vj *Ma[/tex]
[tex]= 934 * ( 4.19 - 77.9 ) - 219 *77.9[/tex]
[tex]= -68845.14 - 17060.1[/tex]
=[tex]-85905.24N[/tex]
delivered power
[tex]= Fth * Vj[/tex]
[tex]= -85905.24N * 219[/tex]
[tex]= -18813247.56W[/tex]
Given:
Horizontal speed = 219 m/sRate of air = 44.9 kg/sFuel combustion rate = 4.19 kg/sExhaust gas ejected = 934 m/sThrust of the engine will be:
→ [tex]F^{th} = Ve(Mf-Ms)-Vj\times Ma[/tex]
By putting the values, we get
[tex]= 934(4.19-77.9)-219\times 77.9[/tex]
[tex]= -68845.14-17060.1[/tex]
[tex]= -85905.24 \ N[/tex]
hence,
The delivered power will be:
= [tex]F^{th}\times Vj[/tex]
= [tex]-85905.24\times 219[/tex]
= [tex]-18813247.56 \ W[/tex]
Thus the solution above is right.
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A microscope using ultraviolet light is used to study bacteria. If the aperture diameter is 1.5 cm and it is desired to distinguish features with an angular size 0.036 arc seconds, what maximum wavelength can be used
Given :
A microscope using ultraviolet light is used to study bacteria. If the aperture diameter is 1.5 cm.
Angular size is 0.036 arc seconds.
To Find :
The maximum wavelength that can be used.
Solution :
Converting given angle into radians :
[tex]\theta = \dfrac{0.036}{3600}\times \dfrac{\pi}{180}\\\\\theta = 1.745\times 10^{-7}\ radians[/tex]
Now, we know maximum wavelength is given by :
[tex]\lambda = \dfrac{\theta \times D}{1.22}\\\\\lambda = \dfrac{1.745\times 10^{-7} \times 0.015}{1.22}\ m\\\\\lambda =2.145 \times 10^{-7}\ m[/tex]
Hence, this is the required solution.
Draw the Free- Body diagram of the 37 kilogram glass falling to the floor in a vacuum.
Then, use Newton’s Second Law to calculate how much force the glass hits the floor with.
Answer:
362.6 N
Explanation:
[tex]F_{g}=mg[/tex]
[tex]F_{g}=37\cdot9.8[/tex]
[tex]F_{g}=362.6\ N[/tex]
Therefore, the force that the glass hits the floor with is 362.6 N
Which electromagnetic waves have the shortest wavelength and the highest frequency?
i tried gamma and it said it was inncorect plz help
An object in space has altitude of 2210 km, velocity of 7000 m/s and flight path angle of 20 degrees. Find the eccentricity, semi-major axis, angular momentum/mass, and kinetic and potential energies/mass
Answer:
Eccentricity = 0.0557
Semi-major axis = 9,095 km
Angular momentum/mass = 60,116 [tex]\frac{km^{2} }{Sec}[/tex]
Kinetic energies/mass = 24,500 KJ
Potential energies/mass = 21,673 KJ
Explanation:
Eccentricity
To find the eccentricity use the following formula
Eccentricity = [ Altitude from the earth x ( [tex]Velocity^{2}[/tex] / Gravitational parameter for the Earth ) ] - 1
Where
Altitude from the earth radius = Radius of the earth + Altitude of the earth from radius = 6,378 km + 2,210 km = 8,588 km
Velocity = 7,000 m/s
Gravitational parameter for the Earth = 3.986004418 × [tex]10^{14}[/tex]
Eccentricity = ?
Placing values in the formula
Eccentricity = [ ( 8,588 km x 1000 ) x ( [tex]7000^{2}[/tex] / 3.986004418 × [tex]10^{14}[/tex] ) ] - 1
Eccentricity = 0.0557
Semi-major axis
Total Distance = Semi-major axis x ( 1 - Eccentricity )
Where
Total Distance = 8,588 km
Eccentricity = 0.0557
8,588 x 1,000 m = Semi-major axis x ( 1 - 0.0557 )
8,588,000 m = Semi-major axis x 0.9443
Semi-major axis = 8,588,000 m / 0.9443
Semi-major axis = 9,094,567.40 m
Semi-major axis = 9,094.56740 km
Semi-major axis = 9,095 km
Angular momentum/mass
L = MVR
L/M = VR
Where
V = Velocity = [tex]\frac{7,000 m/s}{1000}[/tex] = 7 km/s
R = Total Radius = Radius of Earth + Altitude = 6,378 km + 2,210 km = 8,588 km
Placing values in the formula
L/M = 7 km/s x 8,588 km = 60,116 [tex]\frac{km^{2} }{Sec}[/tex]
Kinetic energies/mass
Ke = I [tex]W^{2}[/tex]
Ke = [tex]\frac{1}{2} mr^{2}[/tex] [tex]W^{2}[/tex] ( Where I = [tex]mr^{2}[/tex] )
[tex]\frac{ke}{m}[/tex] = [tex]\frac{r^2}{2}[/tex] [tex]W^{2}[/tex]
[tex]\frac{ke}{m}[/tex] = [tex]\frac{r^2}{2}[/tex] [tex]\frac{V^2}{r^2}[/tex] ( [tex]W^{2}[/tex] = [tex]\frac{V^2}{r^2}[/tex] )
[tex]\frac{ke}{m}[/tex] = [tex]\frac{V^2}{2}[/tex]
[tex]\frac{ke}{m}[/tex] = [tex]\frac{7000^2}{2}[/tex]
[tex]\frac{ke}{m}[/tex] = 24,500,000 J
[tex]\frac{ke}{m}[/tex] = 24,500 KJ
Potential energies/mass
PE = mgh
[tex]\frac{PE}{m}[/tex] = gh
Where
g = 9.807 [tex]\frac{m}{s^2}[/tex]
h = 2,210 km x 1,000 = 2,210,000 m
Placing values in the formula
[tex]\frac{PE}{m}[/tex] = 9.807 [tex]\frac{m}{s^2}[/tex] x 2,210,000 m
[tex]\frac{PE}{m}[/tex] = 21,673,470 J
[tex]\frac{PE}{m}[/tex] = 21,673.470 KJ
[tex]\frac{PE}{m}[/tex] = 21,673 KJ
what is the shallowest part of the ocean ecosystem is called
Answer:
intertidal zone.
the shallowest part of the ocean ecosystem, where the ocean floor os covered and uncovered as the tide goes in and out. Plankton. the organisms that float on the water in aquatic ecosystems and are unable to swim.
How has the magnet affected the block of material next to it?
A. The domains in the end of the block farthest from the magnet are aligned with its magnetic field.
B. The domains in the end of the block closest to the magnet are aligned with its magnetic field.
C. The domains in the center of the block are aligned with the magnetis magnetic field
D. The domains in the entire block are aligned with the magnets magnetic field
Answer: (APE X) B
Explanation: I am taking it and I just got it right
The magnetic characteristics of a substance are determined by the magnetic moments of its atoms, the domains which are closest to the magnet are aligned with its magnetic field, hence option b is correct.
What is the effect of a magnet?Long-range alignments of magnetic moments in ferromagnetic materials, known as domains, include magnetic moments that all point in the same direction.
This indicates that the atoms' individual magnetic moments are lined up with one another and pointing in the same general direction.
Therefore, a magnetic substance will get magnetized if it is placed close to a magnet. Magnetism is the name for this kind of electricity, hence option b is correct.
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a ray of light parallel to the principal axis of spherical mirror
Answer:
This question is incomplete but the completed question is below
A ray of light parallel to the principal axis of a spherical mirror passes through its _____ after reflection.
(a) focus (b) pole (c) centre of curvature (d) imaginary centre of curvature
The correct option is (a)
Explanation:
After reflection, a ray of light will usually appear to diverge after they hit a spherical mirror, extending behind the mirror to meet at a point (called the focus or focal point) between the pole and the centre of curvature of this mirror. Hence, option a is the correct option.
On a part-time job, you are asked to bring a cylindrical iron rod of density 7800 kg/m^3 , length 92.4 cm and diameter 2.15 cm from a storage room to a machinist. Calculate the weight of the rod, w. Assume the free-fall acceleration is g =9.81m/s^2
Answer:
25.68 N
Explanation:
From the question given above, the following data were obtained:
Density of cylindrical rod = 7800 kg/m³
Length = 92.4 cm
Diameter = 2.15 cm
Acceleration due to gravity (g) = 9.8 m/s²
Weight of rod =?
Next, we shall determine the volume of the rod. This can be obtained as follow:
Height (h) = 92.4 cm
Diameter (d) = 2.15 cm
Pi (π) = 3.14
Volume (V) =?
V = π(d/2)²h
V = 3.14 × (2.15/2)² × 92.4
V = 335.29 cm³
Next, we shall convert 335.29 cm³ to m³. This can be obtained as follow:
1 cm³ = 1×10¯⁶ m³
Therefore,
335.29 cm³ = 335.29 cm³ × 1×10¯⁶ m³ / 1 cm³
335.29 cm³ = 0.00033529 m³
Thus, 335.29 cm³ is equivalent to 0.00033529 m³.
Next, we shall determine the mass of the rod. This can be obtained as follow:
Density of rod = 7800 kg/m³
Volume of rod = 0.00033529 m³.
Mass of rod =?
Density = mass /volume
7800 = mass / 0.00033529
Cross multiply
Mass of rod = 7800 × 0.00033529
Mass of rod = 2.62 Kg
Finally, we shall determine the weight of the rod. This can be obtained as follow:
Mass (m) of rod = 2.62 Kg
Acceleration due to gravity (g) = 9.8 m/s²
Weight (W) of rod =?
W = m × g
W = 2.62 × 9.8
W = 25.68 N
Therefore, the weight of the rod is 25.68 N
What type of simple machine is an electric fan?
Answer:
An electric fan is considered to be a mixture of several simple machines. It includes the Wheel and Axle type, wedges, and the Inclined plane types. The blades of an electric fan are the inclined planes and the wedges.
An apple (mass = 0.25 kg) on a string 1 m in length is whirled above a student's head in a circle. The apple has a tangential speed of 12 m/s. What is the magnitude of the centripetal force on the apple?
Answer:
36N
Explanation:
Given parameters:
Mass of apple = 0.25kg
length of string = 1m
tangential speed = 12m/s
Unknown:
magnitude of centripetal force = ?
Solution:
The centripetal force keeps a body moving along a circular path.
It is mathematically derived using the expression below;
F = [tex]\frac{mv^{2} }{r}[/tex]
F is the centripetal force
m is the mass
v is the tangential speed
r is the radius
Now insert the parameters and solve;
F = [tex]\frac{0.25 x 12^{2} }{1}[/tex] = 36N
I AM 145 LBS. I FELL FROM A TABLE TOP THAT WAS 4.5 FEET HIGH AND LANDED ON MY HAND WHICH WAS TURNED BACKWORDS. I BROKE BOTH MAJOR BONES IN MY ARM DIRECTLY ABOVE MY WRIST. WHAT IS THE FORMULA OF THE FORCE AND WEIGHT HITTING THE FLOOR
please write the definition of instantaneous speed, velocity and acceleration and solve problems on them please show workings
Answer:
instantaneous speed: The instantaneous speed is the speed of an object at a particular moment in time. And if you include the direction with that speed, you get the instantaneous velocity. In other words, eight meters per second to the right was the instantaneously velocity of this person at that particular moment in time.
velocity: the speed of something in a given direction.
acceleration: a vehicle's capacity to gain speed within a short time.
solve problems: Problem solving consists of using generic or ad hoc methods in an orderly manner to find solutions to problems.
Explanation:
Roughly speaking, the radius of an atom is about 10,000 times greater than that of its nucleus. If an atom were magnified so that the radius of its nucleus became 2.0 cm, about the size of a marble, what would be the radius of the atom in miles
Answer:
0.124 miles
Explanation:
Since the radius of the atom R = 10000r where r = radius of nucleus. Now, if r = 2.0 cm = 0.02 m,
R = 10000r
= 10000 × 0.02 m
= 200 m
We know that 1 mile = 1609 m.
So the radius of the atom in miles is R = 200 m × 1 mile/ 1609 m = 0.124 miles
So, the radius of the atom in miles is 0.124 miles