Answer:
The Force Of Gravity
Explanation:
The elevator's body diagram has three forces, the force of gravity, a downward normal force from you, and an upward force from the tension in the cable holding the elevator. The combined system of you + elevator has two forces, a combined force of gravity and the tension in the cable.
What is the kinetic energy of a jogger with a mass of 65.0 kg traveling at a speed of 2.5m/s
Answer:
203.1J
Explanation:
Given parameters:
Mass = 65kg
Speed = 2.5m/s
Unknown:
Kinetic energy of jogger = ?
Solution:
To solve this problem, we use the kinetic energy equation:
K.E = [tex]\frac{1}{2}[/tex] m v²
m is the mass
v is the velocity
Now insert the parameters and solve;
K.E = [tex]\frac{1}{2}[/tex] x 65 x 2.5² = 203.1J
A box is sliding on a rough patch of ice, and the only horizontal force acting on it is friction. You observe that it slides to a stop in 600 seconds over a distance of 23 meters. What magnitude coefficient of kinetic friction between the box and the ice?
Answer:
The magnitude of the coefficient of kinetic friction is approximately 1.304 × 10⁻⁵
Explanation:
The given parameters are;
The time it takes for the box to stop, "t" = 600 seconds
The distance the box moves before coming to a stop, "d" = 23 meters
The work done by the friction force to stop the block = The kinetic energy lost by the box
The work done by the friction force to stop the block = [tex]\mu _k[/tex]·m·g·d
The kinetic energy change of the block = 1/2·m·u²
Where;
g = The acceleration due to gravity = 9.8 m/s²
m = The mass of the box
[tex]\mu _k[/tex] = The coefficient of kinetic friction
d = The distance travelled by the block = 600 m
u = The initial velocity of the block
∴ [tex]\mu _k[/tex]·m·g·d = 1/2·m·u²
[tex]\mu _k[/tex]·g·d = 1/2·u²
[tex]\mu _k[/tex] = 1/2·u²/(g·d) = 1/2·u²/(9.8 × 23) = u²/450.8
∴ [tex]\mu _k[/tex] = u²/450.8...(1)
The kinematic equation of motion of the block can be presented as follows;
v = u - a·t
Where;
v = The final velocity = 0 m/s (The block slides to a stop)
u = The initial velocity
a = The acceleration of the block (the minus sign indicates that the block's velocity is decreasing)
t = The time of motion of the block = 600 seconds
Therefore, by substituting the above values, we have;
0 = u - 600·a
∴ u = a·600
The kinematic equation of motion for the distance moved by the block, "s" can be expressed as follows;
s = u·t - 1/2·a·t²
Where;
s = The distance moved by the bloc = 23 meters
∴ 23 = a·600·600 - 1/2·a·600² = 360,000·a - 1/2·a·360,000 = 180,000·a
a = 23/(180,000)
u = 600 × (23/(180,000)) = 23/300
The initial velocity, u = 23/300 m/s
From equation (1), we have;
[tex]\mu _k[/tex] = u²/(450.8) = (23/300)²/450.8 = 23/1764000 ≈ 1.304 × 10⁻⁵
The magnitude of the coefficient of kinetic friction, [tex]\mu _k[/tex] ≈ 1.304 × 10⁻⁵
How many protons does Aluminum have?
Answer:
The atomic number of Aluminum is "13"!
Explanation:
The 27 means the atomic mass is 27 . The number of protons plus the number of neutrons is 27. That means the number of neutrons is 27–13=14. Number of neutrons depends on the isotopic form of aluminium.
A car is traveling at a constant speed of 60km/h but then changes lanes. Even traveling at a constant speed, the car's velocity is changing. Explain
Answer:
Yes. Anytime the velocity is constant, the acceleration is zero. For example, a car traveling at a constant 90 km/h in a straight line has nonzero velocity and zero acceleration.
:)
brainlest plz, i really need it
Two cars bump going the same direction and stick together. Car A has a mass of 1000kg car B has a mass of 2000kg. What the speed of the cars after the collision?
Answer:
I belive that the 2000 kg will be going faster then the 1000kg
Explanation:
Because it is 2x as heavy as the other car which means it most likely would hit the car and keep going because it can hit it so hard that the car dosent hit effected
Please I need help with this question (see image).
Show workings where necessary.
Answer:
Qúéßtîóñ : A quantity of pepper soup of mass 800g poured into a plastic container with a tight fitting lid has a temperature of 30oC. The container is then placed in a microwave oven, rated 1200 W and operated for3 minutes.
(i) Calculate the final temperature attained by the soup. (Assuming no heat losses)
Àñßwër : Pt = mc
1200 x 3 x 60 = x 4000 x
= 67.5o
Final temp = 67 . 5o + 30o
= 97.5oC
(ii) Explain why containers with tight-fitting lids are not suitable for use in microwave cooking.
Àñßwër : The molecules of the steam from the content are confined within the container. As the temperature increases the rate of collision of the molecules with walls of the container increases, thus the pressure inside the container increases. If it is tightly fitted, the pressure can make the container burst thus releasing its hot content.
(iii) When the soup is brought out and allowed to cool, a dent was observed on the container. Explain.[ Take specific heat capacity of the soup = 4000 Jkg-1 K-1 ]
Àñßwër: The container will dent because the condensation of the steam in the container will lead to a decrease in pressure in the container making the atmospheric pressure greater than the pressure in the container.
Explanation:
______❤️ hope it helps you ❤️________In the picture to the right, find the angle at which
the box is pulled if the work done is 50J
Answer:
42 °
Explanation:
From the question given above, the following data were obtained:
Force (F) = 45 N
Workdone (Wd) = 50 J
Distance (d) = 1.5 m
Angle (θ) =.?
Angle at which the box is pulled can be obtained as:
Wd = Fd × Cos θ
50 = 45 × 1.5 × Cos θ
50 = 67.5 × Cos θ
Divide both side by 67.5
Cos θ = 50 / 67.5
Cos θ = 0.7407
Take the inverse of Cos
θ = Cos¯¹ 0.7407
θ = 42.2 ≈ 42 °
Thus, the angle at which the box is pulled is approximately 42 °.
Evaporation requires the particles to _____ energy.
Answer:
create
release
absorb
destroy
Answer:
Release
Explanation:
The water is heated until
On a hot day, a child drinks all the water in a plastic bottle. She then screws the
cap back tightly on the bottle, so that the bottle contains only air. She throws the
bottle into a wastebasket, where the Sun shines on it. After a while in the Sun's rays,
the air in the bottle is much hotter than before.
cap screwed on
(i) State what has happened to the pressure of the air in the bottle.
Give a reason for your answer.
(ii) In terms of the behaviour of the air molecules, explain your answer
to a(i)
What is the period of a wave that has a wavelength of 1 meter and a speed of 20 m/s?
Answer:
0.05s
Explanation:
frequency = speed / wavelength = 20/1 = 20Hz. Thus period = 1/f = 1/20 = 0.05 s
This question involves the concepts of wave speed and wavelength.
The period of the wave is "0.05 s".
Period of the WaveThe wave speed is given in terms of wave frequency and wavelength as follows:
[tex]v=f\lambda\\\\f=\frac{v}{\lambda}[/tex]
where,
v = wave speed = 20 m/sλ = wavelength = 1 mf = frequency of wave = ?Therefore,
[tex]f=\frac{20\ m/s}{1\ m}\\\\[/tex]
f = 20 Hz
Now, the period of the wave is the reciprocal of the frequency of the wave:
[tex]Period = T=\frac{1}{f}\\\\T=\frac{1}{20\ Hz}[/tex]
T = 0.05 s
Learn more about wavelength here:
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What is an atom? Please helpppppp
What would the acceleration be for a car at a stop light that
speeds up in the North direction to 20 m's in 10 s?
HELP PLA
Answer:
a = 2 m/s^2
Explanation:
the solution is already done for you. Its just whats 20 divided by 10 which is 2.
can someone help me :(
Answer:
Where is the question?
Explanation:
plzzzzz helppppp plzzzzzzzzzzzzzzzzzzzzzzz
What happens when a wave enters a different material and slows down?
o
A. Refraction
o
B. Transmission
o
C. Reflection
D. AbsorptionWhat happens when a wave enters a different material and slows down?
o
A. Refraction
o
B. Transmission
o
C. Reflection
D. Absorption
Answer:
A
Explanation:
ap3x
Answer:
A. Refraction
Explanation:
<3
b. Find the centripetal force needed to keep an 60.0 kg rider traveling in a circle in the ride.
Given:
m =
v = (from part a)
r=
Unknown:
F=?
Equation:
F= m (v^2) / r
Answer:
loloololo
lol
Explanation:
lolloolololo
can i get sum help ........................
Air is made up of gas particles. These particles exert pressure on every object they collide against. This pressure is known as air pressure. Which of the following statements about air pressure is true?
A.
Warm air tends to have a higher air pressure than cold air.
B.
Air pressure decreases as altitude increases.
C.
The atmosphere's air pressure does not vary.
D.
Air pressure increases as altitude increases.
plz answer CORRECTLY and don't delete or report bc ppl keep doing that to me...
THANKS FOR THE HELP!!!!
Answer:
I think the anwser is b
Explanation:
because as altitude increase pressure therefore decreases
A girl police light on level ground with a force of 45 N at a 30° angle above the horizontal the girl pulls a sled 7.3 m how much work does she have do
Explanation:
W=Fdcos0
=45×7.3cos30
=284.4J
a car’s gas tank contains 58.7 kg of gasoline, which takes up 0.0814 m^3 of volume. what is the density of the gasoline?
unit = kg/m^3
Answer: 721.13
Explanation:
The density of the gasoline will be "721.13 kg/m²". To understand the calculation, check below.
Density and VolumeAccording to the question,
Mass, m = 58.7 kg
Volume, V = 0.0814 m³
We know the relation,
→ Density = [tex]\frac{Mass}{Volume}[/tex]
or,
→ d = [tex]\frac{m}{V}[/tex]
By substituting the values, we get
= [tex]\frac{58.7}{0.0814}[/tex]
= 721.13 kg/m²
Thus the above approach is correct.
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Which of the following is a measurement of acceleration?
O 33 km/h^2
O 20 m/s
O 300 m/s north
O 780 m/s^2 north
Answer:
D
Explanation:
i did that yesterday and your welcome homie b
Why is the line on the Distance-Time graph
curved, but straight on the Speed-Time?
Answer:
because the distance increased while the speed stayed the same
Explanation:
Answer: A curved line on a distance time graph tell us that the speed is changing but the object is either getting faster or the accelerating or slowing down the decelerating.
Explanation: Hope this helps
What type of energy is stored in the nucleus of an atom?
Answer:
Nuclear energy
Explanation:
The nucleus holds the energy together
A crate of books is dragged horizontally across a rought floor at a constant
velocity. If the normal force acting on the crate is 66 Newtons, determine the
mass of the crate.
Answer:
m = 6.73 kg
Explanation:
Given that,
The normal force acting on the crate = 66 N
We need to find the mass of the crate.
Normal force = weight of the crate
N = mg
m is mass of the crate
[tex]m=\dfrac{N}{g}\\\\m=\dfrac{66}{9.8}\\\\m=6.73\ kg[/tex]
So, the mass of the carte is 6.73 kg.
All objects _
energy.
Answer:
Explanation:
All objects radiate energy.
An ocean fishing boat is drifting just above a school of tuna on a foggy day. Without warning, an engine backfire occurs on another boat 1.0 km away. How much time elapses before the backfire is heard by the fish (a)
Answer:
0.641 seconds
Explanation:
Distance (d) = 1.0 km
Using the relation :
Speed = distance / time
Time = distance / speed
Speed of sound in seawater is about 1560 m/s
Distance = 1.0km =
1km = 1000m
Time = 1000 / 1560
Time = 0.6410256
Time = 0.641 s
If the astronaut in the video wanted to move upward, in which direction should he throw the object? Why?
1.He should throw the object upward because according to Newton’s third law, the object will then exert a force on him in the same direction (i.e., upward).
2.He should throw the object upward because according to Newton’s third law, the object will then exert a force on him in the opposite direction (i.e., downward).
3.He should throw the object downward because according to Newton’s third law, the object will then exert a force on him in the opposite direction (i.e., upward).
4.He should throw the object downward because according to Newton’s third law, the object will then exert a force on him in the same direction (i.e., downward).
Answer:
3.
Explanation:
If the astronaut in the video wanted to move upward, he should throw the object downward because according to Newton’s third law, the object will then exert a force on him in the opposite direction (i.e., upward). hence, option (3) is correct.
What is Newton's third law of motion?Newton's Third Law states that if object A exerts a force on object B, then object B must apply a force to object A that is equal in magnitude and directed in the opposite direction.
This law represents a specific symmetry in nature: forces always exist in pairs, and no body can exert a force without also being subjected to one.
Hence, if the astronaut in the video wanted to move upward, he should throw the object downward and the object will then exert a force on him in the opposite direction (i.e., upward).
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In the middle of your Fitness drug you start to feel a little weak selective method of monitoring your Fitness level which would be readily available to you at the least cost: A. Heart rate monitor B. Pedometer C. Talk test D. Stopwatch
Answer:
C. Talk test
Explanation:
The talk test would be readily available to me at the the least cost.
The talk test is about the easiest way that one can monitor intensity as they exercise. Because the only thing needed here is the ability to talk and to breathe.
The intensity lies on if one can talk and breathe at the same time. The harder one exercises, the more breathless they become and they find it difficult to talk.
Answer:
c
Explanation:
why does of beam of light ben when it passes into a new medium?
Answer:
The bending occurs because light travels more slowly in a denser medium.
Given two magnets, in which position will they attract? In which position will they repel?
Answer:
They will attract when its north and south but will repel when its south and south or north and north
Are certain forms or methods of weathering more common in certain environments? For example, where do you think
you'd see exfoliation or ice wedging occur more commonly?
Answer:
Yes
Explanation:
Certain types of weathering are more common in certain environments than others.
This is very true.
Weathering is the physical disintegration and chemical decomposition of rocks to form sediments and soils. Different forms of weathering are dictated by their geographies on the earth surface. Ice or frost wedging is only possible in temperate or polar regions of the world. Exfoliation is pronounced around the tropical region as series of thermal expansion and contraction is involved. Alternate freezing and thawing which expands cracks is also a geographical phenomenon.