Calculations
A cart is pushed with 12 N of force across a floor for 2 m. How much work was done?
24 J
What does the Law of Conservation of Energy state?
What is the unit for Power?
Watts
What is the energy of motion?
Kinetic energy
A 0.09 kg marble is up on a roller coaster .84 m in the air. What is the marbles potential energy?
0.74 J
If a marble has 0.3 J of potential energy at the top of ramp, what is its kinetic energy at the bottom if you neglect air resistance?
0.3 J
What is the equation for work?
Work equals Force times Distance
Potential Energy
A 3 kg squirrel is running out of Christmas tree at 6.8 m/s. What is its kinetic energy?
69.36 J
A model rocket falls out of the sky where it had 400 J of potential energy at its highest point. If it has 250 J of kinetic energy at the bottom, what happened to the 150 J of energy not accounted for?
It became thermal energy
If someone does 600 J of work on a 40 kg object, how far did they move?
15 m
What is the energy you have due to being some distance off the ground?
Gravitational Potential Energy
A 300 kg crate is pushed up a 2.5 m ramp in 3.6 s. What is the power of the person moving the crate?
2083.3 W
Why can a roller coaster never go higher than the first hill it drops down?
Because it can never gain more energy that it had at the beginning
If a person lifts a 200 lbs bar and then sets it back on the rack where it came from, how much work have they done?
0 J
Light, sound, nuclear, chemical, thermal, electrical
A car's parking break gives out and it rolls down a hill. If the 2500 kg car is going 10 m/s at the bottom of the hill, how high was the hill?
5.1 m
If an object with 1000 J of potential energy falls and 30% of its energy is lost to thermal energy, what is its kinetic energy at the bottom?
700 J
If you carry a stack of 7 texts books that weighs 60 N down the 20 m hallway, how much work have you done?
0 J
What types of energy make up mechanical energy?
Kinetic, Gravitational, and Elastic