Gravity
What is the acceleration due to gravity?
9.8m/s^2
What force keeps the moon in orbit around Earth?
Gravity. Earth's gravitational pull attracts the moon into an orbit.
What Happens to the total mechanical energy of an object when there are no external forces acting on it (like friction)?
Total mechanical energy will remain constant. This is known as the conservation of mechanical energy.
No. Given by th equation U = mgh, potential energy will increase when height increases.
A rock is dropped from a cliff. How fast is it moving after 3 seconds? (use g = 9.8m/s^2)
29.4m/s downwards
The International Space Station orbits Earth at an altitude of 400 km. What is its orbital speed?
v = 7667.07m/s
A 10 kg box is lifted 2 meters off the ground. What is the gravitational potential energy gained by the box?
U = 196J
If a pendulum is swung back and forth, how does its mechanical energy change? (assuming no friction)
It will not change
An object is dropped from rest and takes 4 seconds to reach the ground. How high was it dropped from?
78.4m
A satellite orbits Earth at an altitude of 500 km. Find its orbital period (in seconds)
T = 5677.967s
A 5 kg ball is thrown upwards with an initial velocity of 10 m/s. How high does the ball rise before it starts to fall back down?
h = 5.1m
If a pendulum is swung back and forth, how does its kinetic and potential energy change?
When the pendulum swings down, its potential energy is converted back into kinetic energy, and vice versa when it swings back up.
A ball is thrown straight up with an initial velocity of 20 m/s. How long does it take to reach its highest point, and what is the maximum height it reaches?
t = 2.04s, max = 20.4m
Calculate the escape velocity from the Moon’s surface.
V = 2376.58m/s
A car of mass 1000 kg accelerates from 0 to 20 m/s over a distance of 100 meters. How much work was done to accelerate the car?
W = 200,000J
How does escape velocity relate to mass?
Given by the formula V = sqrt (2GM/r), the greater the mass of the planet/star is, the greater your velocity will be to "escape" it.