A cement block accidentally falls from rest from the ledge of a 55.9-m-high building. When the block is 11.2 m above the ground, a man, 1.70 m tall, looks up and notices that the block is directly above him. How much time, at most, does the man have to get out of the way?
Answers
Answer:
0.3 seconds approximately
Explanation:
Given that the height of the building is 55.9 m and cement block accidentally falls from rest from the edge of a 55.9-m-high building. The initial velocity of the block will be equal to zero. The final velocity will be achieved by using the formula:
V^2 = U^2 + 2gH
Where g = 9.8 m/s^2
H = 55.9m
V^2 = 0 + 2 × 9.8 × 55.9
V^2 = 1095.64
V = sqrt(1095.64)
V = 33.1 m/s
The velocity When the block is 11.2 m above the ground will be 33.1 m/s and the height h = 11.2 - 1.7 = 9.5 m
The time of escape can be calculated by using the formula;
h = Ut + 1/2gt^2
9.5 = 33.1t + 1/2 × 9.8 × t^2
9.5 = 33.1t + 4.9t^2
4.9t^2 + 33.1t - 9.5
By using quadratic formula to calculate the time, the negative value is ignored and the positive values will be the time the man has to get out of the way.
Please find the attached file for the remaining solution.
Related Questions
A boy runs 20 M/sec and after 4 sec velocity become 10m/sec find the acceleration
Answers
Explanation:
Hey, there!!!
Here,
Given that,
initial velocity (u)= 20 m/s
final velocity (v)= 10 m/s
now,
[tex]acceleration \: = \frac{v - u}{t} [/tex]
[tex]a = 10-20/4
[tex] a= -2.5m/s^2
Therefore, theacceleration is -2.5m/s^2.
{ it gives negative acceleration because final velocity is decreased }.
Hope it helps....
Answer:
-2.5 m/(s^2)
Explanation:
Acceleration = Final Velocity - Initial velocity / Time
=> Acceleration = 10 - 20 /4
=> Acceleration = -10/4
=> Acceleration = -5/2
=> Acceleration = -2.5 m/(s^2)
Anwer this quickly.... Find the equivalent capacitance of the following combination.
Answers
Answer:
When we have capacitors in series, with capacitances c1, c2, ...., cn, the total capacitance can be obtained from the equation:
1/ct = 1/c1 + 1/c2 + .......
When we have capacitors in parallel, with capacitances c1, c2, ..., cn, the total capacitance can be obtained from the equation:
ct = c1 + c2 +......
Ok, in this case we have two branches, and in each branch we have two capacitors in series.
So the capacitance of each branch will be:
1/ct = 1/c + 1/c = 2/c
ct = c/2.
Now we can think that we have two capacitors in parallel, each one with capacitance c/2.
So the total capacitance is:
ct = c/2 + c/2 = c.
Polar bears are extremely good swimmers and can travel as long as 10 hours without resting. If a polar bear is swimming with an average speed of 2.6m/s how far will it have traveled after 10.0 hours? (Convert hours for seconds)
Answers
Answer:
It travels 93600 m
Explanation:
speed = 2.6 m/s
time = 10 hour
10 hour = 10 x 60 x 60 = 36000 s
distance = speed x time = 2.6 x 36000 = 93600 m
Make the following prefix conversions.
600,000 cm= ?? km
i need help
Answers
Answer:
6 km
Explanation:
A kilometer is 100,000 centimeters, so 600,000 centimeters equals 6 kilometers.
How is heat measured?
Answers
Answer:
Measurement of heat is done in calories. One calorie is the amount of energy required to raise one gram of water one degree Celsius. To measure heat, you divide the change in temperature of a sample of water by the mass of the water.
Answer:
To measure heat, you divide the change in temperature of a sample of water by the mass of the water.
Explanation:
The way we can measure that heat is by using something called the Calorie.
express 0.0097 in scientific notation
Answers
Explanation:
Move the decimal point until it is behind the first non-zero digit.
In this case, we move it 3 places to the right so it is behind the 9.
Therefore, 0.0097 = 9.7×10⁻³.
A body of mass 10 kg is pulled along a horizontal floor by a horizontal force of 48 N with an acceleration of 3.0 ms?. Calculate the frictional force between the body and the floor.
Answers
Answer:
18 Newtons
Explanation:
The unbalance force is 10kg ×3m/s2= 30N
frictional force = 48-30= 18N
Help me please !!!!!! I really need help !!!!!! A spring is compressed, resulting in its displacement to the right. What happens to the spring when it is released? The spring exerts a restoring force to the right and returns to its equilibrium position. The spring exerts a restoring force to the right and compresses even further. The spring exerts a restoring force to the left and stretches beyond its equilibrium position. The spring exerts a restoring force to the left and returns to its equilibrium position.
Answers
Answer:the spring exerts a restoring force to the left and returns to its equilibrium position
Explanation:
Answer:
The spring exerts a restoring force to the left and returns to its equilibrium position.
Explanation:
What kind of acceleration does an object have if it’s speeding up
Answers
Answer:
uniform acceleration
Explanation:
when an object is moving in the same speed then an object is going on uniform acceleration
The mass of density bottle of volume 50cm3 is 10g when empty. Aluminium turnings are poured into the bottle and the total mass is 60g. Water is then added into the turnings till the bottle is full. If the total mass of the bottle and its contents is 90g, calculate the density of the aluminium turnings.
Answers
Total density = T. mass / T. Volume.
= 90/ 50
= 1.8 gm/ cm3
Now,
Mass of Water = 90 - 60
= 30 gm.
Volume = 50cm3
Density = Mass/ Volume
= 30/ 50
= 0.6 gm /cm3
Now,
Density of Aluminium = 1.8 - 06
= 1.2 gm/ cm^3
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who is the father of science?
Answers
I hope this helps you
Your question has been heard loud and clear.
Gallelio Galei is truly the father of modern sciences. Well I mean he had a cool beard , but he still was intelligent.
Thank you
Very little is known about Pluto's surface conditions. TrueFalse
Answers
The statement is true.
what are the differences and the similarities between psychology and the social science
Answers
Answer:
psychology has to do with the mind and brain while social science has to do with the scientific study if human relationships
There are cars with masses 4 kg and 10 kg respectively that are at rest. A car having the mass 10 kg moves towards the east with a velocity of 5 m.s-1. Find the velocity of the car with mass 4 kg with respect to ground.
Answers
Answer:
The velocity of the car of mass 4 kg with respect to ground is 0 m/s
Explanation:
The problem initially stated that the car is at rest. at this stage, the velocity of the car relative to the ground is already = 0 m/s.
When the 10 kg car began to move, the problem did not specify at any point that the 4 kg car began to move also. Hence, the motion of the 10 kg car did not affect the 4 kg car in any way.
As a result, relative to the ground, the velocity of the 4 kg car is still 0 m/s since no motion was recorded by the car.
Imagine you and your friend are trying to rearrange the furniture in your classroom. You push on a desk with a force of 100 n to the right ,your friendpushes on the same desk with a force of 80 n to the left .What is the net force on the desk
Answers
Answer:20n Force :Right
Explanation:
The Answer To the equation is 20n because If the net force is opposite ways you subtract and the net force is the highest number !
factors that affect acceleration due to gravity.
Answers
Answer
Factors Affecting Acceleration Due to Gravity
(1) Position on the planetary surface, it is higher at the axis (poles),
(2) Mass of the planet, higher with planets of larger masses
(3) Distance between object and the centre of planet, the larger the distance, the smaller the acceleration due to gravity.
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Explanation:
the factors affecting acceleratiom due to gravity are:
Altitude above the earth’s surface.Depth below the earth’s surface.The shape of the earth.Rotational motion of the earth.Question 3
What natural event do scientists blame for the desertification taking place in South Africa?
Answers
Answer:
Explanation:
Overgrazing and woodcutting are responsible for most of the desertification of rangelands, cultivation practices inducing accelerated water and wind erosion are most responsible in the rain-fed croplands, and improper water management leading to salinization is the cause of the deterioration of irrigated lands.
The speedometer of a car moving east reads 60 mph. It passes another car that moves west at 60 mph. Which statement is the most accurate description of the motion of the vehicles?
Answers
Answer:
correct statement should be the same speed.
Explanation:
if the car is moving east reads 60 mph and it passes another car with the same speed.
therefore, the magnitudes of their velocities are equal.
and each car's velocity is the negative of the other car vehicle.
so the correct statement should be the same speed.
Answer:
They have different velocities
Explanation:
The cars are passing each other at the same speed, and because velocity is speed with direction they are at different velocities.
As the space shuttle orbits the Earth, the shuttle and the astronauts
accelerate towards the Earth with the same acceleration. What effect does
this create?
Answers
Answer:
a=g.
the body is in one of these INGRAVIDITY, so the weight of the body would be ZERO
Explanation:
When the spacecraft revolves around the Earth, it is subjected to Newton's second law
F = m a
where the force is the universal attractive force, the mass of the astronauts, and the centripetal acceleration.
a = F / m
a = (G M m / r²) / m
a = G M / r²
the amount of is the acceleration of gravity at height r.
a = g
Therefore, we see that the acceleration of the body is equal to the acceleration of gravity, which is why the body is in one of these INGRAVIDITY, so the weight of the body would be ZERO
Differentiate between rest and motion.
Answers
Answer:
1. A body is said to be at rest if its position does not change with respect to its surroundings.
how much work is done in moving a charge of 3 coulomb for a point at the volts 115 to a point at 125 volts
Answers
Answer:
We use the Formula,
Work done = total chargr×potential difference
W=Q(total)× V
Here
Q= total charge= Give 3c
V=potential difference= 10v
so the work done in moving the charge from A to B will be,
w=3×10
w= 30 joules
Mercury has a density of 13.56 g/mL. How many kilograms of mercury would you expect to fit in a cylindrical glass cup with a bottom radius of 5.75 inches and a height of 0.950 ft?
Answers
Answer:
263.152kg
Explanation:
The density of a substance is related to its mass and volume as follows;
density = mass / volume
mass = density x volume -------------(i)
The substance in question here is mercury which has;
density = 13.56g/mL = 13.56g/cm³
Since the mercury is going to be put in the cylindrical glass, the volume of the cylindrical glass is going to be equal to the volume of the mercury that will be put.
And we know that the;
volume of a cylinder = πr²h
Where;
π = 3.142
r = bottom radius of the cylinder = 5.75inches
h = height of the cylinder = 0.950ft
For uniformity, let's convert the radius and height of the cylinder to their corresponding values in cm
r = 5.75 inches = 5.75 x 2.54 cm = 14.605cm
h = 0.950 ft = 0.950 x 30.48 cm = 28.956cm
Therefore, the volume of the cylinder;
v = 3.142 x (14.605cm)² x 28.956cm = 19406.5cm³
v = 19406.5cm³ [This is also the volume of the mercury necessary to fit the cylinder]
Now the following value has been found;
volume = 19406.5cm³
Substitute the values of density and volume into equation (i) as follows;
mass = 19406.5cm³ x 13.56g/cm³
mass = 263152.14g
Convert the result to kg by dividing by 1000
mass = 263.152kg
Therefore, 263.152kg kilograms of mercury would fit in the cylindrical glass.
Materials are called if they can catch on fire when they are exposed to a flame or hot temperature.
Answers
They are called flammable.
Answer:
A material that is able to catch on fire is called a combustible material. It 8s easily able to catch on fire with any flames near by or by the surrounding temperatures
If E=1/2Av^2+Bmx find the dimensions of A and B(Where E is energy,v,m and x are velocity,mass and distance respectively)
Answers
Answer:
A = [kg]
B = [m/s²]
Explanation:
E = ½ Av² + Bmx
Substitute the units:
[J] = ½ A [m/s]² + B [kg] [m]
A Joule written in base units is:
1 J = 1 Nm = 1 kg m²/s²
Each term must have the same units.
[kg m²/s²] = A [m/s]²
[kg m²/s²] = A [m²/s²]
A = [kg]
[kg m²/s²] = B [kg] [m]
B = [m/s²]
When kinetic and potential energy are equal???
Answers
Answer:
No there aren’t equal
Explanation:
An object is observed to move under the following equation of motion ... x(t) = A√t ... take A =√2. Determine the equations for the velocity and acceleration as a function of time. Write each equation in differential equation format, including second-order, if necessary.
Answers
Explanation:
x(t) = A√t
x(t) = √(2t)
v(t) = dx/dt
v(t) = ½ (2t)^-½ × 2
v(t) = (2t)^-½
a(t) = dv/dt
a(t) = -½ (2t)^⁻³/₂ × 2
a(t) = -(2t)^⁻³/₂
the unit of measurement of temperature is degree ______ Or degree __________
Answers
Answer:
none of above. The answer is celsius
Answer:
[tex]^{O} C[/tex] (Degree Celsius) and [tex]^{O}F[/tex] (Degree Fahrenheit)
Explanation:
It can be Degree Celsius or Degree Fahrenheit.
The S.I unit of measurement of temperature is Kelvin. (K)
If the magnetic field is held constant at 3.0 T and the loop is pulled out of the region that contains the field in 0.2 s, what is the magnitude of the average induced emf in the loop
Answers
Answer:
emf = 15 * Area and if A is given in square meters, the units of the emf will be Volts
Explanation:
Assuming that the area of the loop of current (A) is known, the magnitude of the induced emf can be calculated using Faraday-Lenz's Law:
[tex]emf=|-\frac{\Delta\,\Phi}{\Delta \,t} |=|\frac{A\,B}{\Delta \,t}|=|\frac{A\,(3)}{0.2}|=15\,A[/tex]
and if the area (A) is given in square meters, the emf will directly come in units of Volts.
7. What is the kinetic energy of a 3-kilogram ball that is rolling at 2 meters per second?
Answers
Answer:
6Newton meter is the answer.
Explanation:
Mass=m=3kg
Velocity=v=2m/s
Kinetic energy =K.E.=?
As we know that
K.E.=1/2mv^2
Putting the values
K.E.=1/2✖️3kg✖️(2m/s)^2
K.E.=1/2✖️3kg✖️4m^2/s^2
K.E=1/2✖️12Nm
K.E.=6Nm is your answer
Hope it will help you :)
The kinetic energy of a 3-kilogram ball that is rolling at 2 meters per second is E = 6 joules.
To find the Kinetic Energy, the given details are
Mass of the ball, m = 3 kg
Speed of the bag, v = 2 m/s
What is Kinetic Energy?An object with twice as much mass and the same speed will have twice as much kinetic energy, whereas an object with twice as much mass and the same speed will have four times as much kinetic energy.Kinetic energy is the kind of energy an object or particle has because it moves.When a net force is applied to an object, which is work that transfers energy, the object accelerates and gains kinetic energy.A moving object or particle's kinetic energy is a property that is affected by its mass as well as its motion.The energy that is possessed due to the motion of an object is called the kinetic energy of the ball.
Its formula is given by :
E = 1/2 mv²
E = [tex]\frac{1}{2}[/tex] (3)(2)²
E = 6 joules
So, the kinetic energy of the ball is 6 joules. Hence, this is the required solution.
Learn more about Kinetic Energy,
https://brainly.com/question/18791288
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what is the speed of a car that travels 25km in 15 minutes?
Answers
Answer:
[tex] \boxed{ \bold{ \huge{ \boxed{ \sf{27.78 \: m/s}}}}}[/tex]Explanation:
Given,
Speed of a car = 25 km
Converting 25 km into m
[tex] \sf{1km = 1000m}[/tex]
[tex] \sf{25 \: km = 25 \times 1000m = 25000m}[/tex]
Time taken ( t ) = 15 minutes
Converting minutes into seconds
[tex] \sf{1 \: minutes = 60 \: seconds}[/tex]
[tex] \sf{15 \: minutes = 15 \times 60 sec = 900 \: seconds}[/tex]
Finding the speed of the car
[tex] \boxed{ \sf{speed = \frac{distance \: travelled}{time \: taken} }}[/tex]
[tex] \sf{ = \frac{25000 \: m}{900 \: s} }[/tex]
[tex] \sf{ = 27.78 \: m/s}[/tex]
Hope I helped!
Best regards!!