Work and Power
A 1200 kg car travels 80 m over 7 seconds. How much work was done by the car?
13,714.29 J
A 175 kg person stands at the top of a cliff. The cliff is 23 m tall. What is this person’s potential energy?
4025 J
A ball is dropped and a ball is thrown horizontally from the same height at the top of a cliff. Both balls have the same mass. Which ball hits the ground first?
They both hit the ground at the same time!
What are three ways heat can transfer?
Conduction, convection, and radiation
What do we call it when energy is not created nor destroyed, only transferred to other forms?
The conservation of energy
Someone pushes a 45 kg box 6 m, accelerating at 7 m/s2. How much work did they do on the box?
1890 J
Someone drops a rock off the top of a building. It has fallen for 6 seconds. The rock’s mass is 4.50 kg. What is the rock’s kinetic energy?
7779.24 J
A person throws a ball off a cliff. It takes the ball 7 seconds to hit the ground. The ball hurdles through the air at 8 m/s before it hits the ground.
How far up is the cliff? How far down range did the ball travel?
240.1 m, 56 m
Define specific heat capacity and one example for high specific heat capacity and one example for low specific heat capacity.
Specific heat capacity is the amount of pockets something has that can store heat energy.
Why would you feel weightless in an elevator whose cord snaps and starts falling? Are you ever truly weightless?
Never weightless, it only feels like it because you are falling at the same rate as the elevator, so you have so support force.
A cheerleading squad lifts up a squad member with a mass of 52 kg. They lift her up 3 m off the ground in 2 seconds. How much power was used?
764.4 watts
Someone is walking at a pace of 6 m/s. Their mass is 56 kg. What is their kinetic energy?
1008 J
Someone shoots a bow and arrow off the side of a cliff. The arrow moves at 15 m/s and hits the ground in 6 s. How far down range did the arrow travel?
90 m
Define sublimation
When a solid skips being a liquid and goes straight to being a gas.
An object is placed at the center between the earth and the moon. What will happen to the object and why?
It will fall towards Earth because Earth has more gravity.
A crane lifts a 435 kg rock 4 m in 6 seconds. How much power was exerted by the crane?
2842 watts
A cliff has a height of 90 m. An object at the top has a potential energy of 7,000 J. Say it falls. What is its kinetic energy right before it hits the ground?
7000 J
A person hurls themself off a diving platform. They reach a velocity of 3 m/s and hit the water of the pool in 2 seconds. What was their range?
6 m
Does evaporation heat or cool?
Evaporation is a cooling process
If a person with the force of 400 N is three Earth-radii far away from Earth, what is their force at that distance?
44.4 N
Someone gives their 106 kg buddy a boost to climb a tree. They lift them up 2.65 m off the ground in 2 seconds. How much power was exerted?
1376.41 watts
A 356 kg bus drives down the road at 50 m/s. What is its kinetic energy?
445000 J
An airplane travels through the air at 79 m/s. In 45 seconds, how far did it travel?
3555 m
Does condensation heat or cool?
Condensation is a warming process.
A 458 kg bus drives down the road at 60 m/s. What is its momentum?
27480 kgm/s