Work & Power
How much work is done by a 0.47N force?
0.12 J
What is the kinetic energy of a 45 g golf ball travelling at 20 m/s?
9J
A shotputter releases a 5.00 kg shot from 2.00m above the ground. If it is moving at 15m/s, what is its total mechanical energy?
661J
A spring stretches 12cm when 100g are suspended from it end. What is the spring constant?
8.2 N/m
An apple a day keeps the doctor away, but in 1687, gravity must have scared this man with fruit, as well.
Who is (Sir) Isaac Newton
How far will a mother push a 20.0kg stroller, using a force of 62N, while she does 2920J of work?
47m
How high would you have to lift a 1000kg car to give it a potential energy of 2000J?
0.2m
Some children go tobogganing on an icy hill that is 10m high. The toboggan and children have a combined mass of 90kg. How fast are they going at the bottom of the hill?
14m/s
How much energy is stored in an elastic band that is stretched 75cm? The spring constant is 12N/m.
3.375J
These kinds of radioactive photons certainly won't turn you green, but you may get angry as they can easily damage your tissue and DNA.
What are gamma rays?
A lawn mower does 900,000J of work in 0.500h. What is its power?
500W
How fast must a 1000kg car be going in order to have 20,000J of kinetic energy?
6.3 m/s
A rodeo rider is thrown off a bucking bronco that is 1.6m above the ground. If he is moving at 4.0m/s, how high is he thrown?
2.4m
A spring with k = 10,000 N/m obeys Hooke’s Law. How far must it be stretched for its potential energy to be 100J?
14cm
In 1943, before throwing it over your stairs, this "wonderful toy" was invented by Richard James, trying to keep boat equipment steady at sea.
What is a Slinky?
How long would it take a 500W electric motor to do 150,000J of work?
300s
How much elastic potential energy does a spring with spring constant 120 N/m have when it is stretched 25cm?
3.75J
A toboggan and kids (mass = 120kg) slides down a 15 m hill. They are moving at 1.2 m/s at the top. If they lose 35% of their energy to friction as they come down the hill, how fast will they be going at the bottom?
14m/s
A 3kg object is at the top of a 5m high ramp. It slides down the ramp and strikes a spring with k = 400 N/m. How much will the spring be compressed?
0.85m
While this man was looking into wave functions of quantum-mechanical systems, he was also trying to determine whether or not his cat was alive without opening the box.
Who is Erwin Schrödinger?
A chair lift takes skiers to the top of a 300m high mountain. The mass of a skier and equipment is 80kg. The lift can bring three skiers to the top every 30s. What is the power required to do this?
23,500W
What kinds of energy does a bungee jumper possess at the bottom of the jump/end of the cord?
Elastic potential and gravitational potential
A roller coaster cart has 12,546 J of energy at the top of the first loop. Neglecting friction, how much mechanical energy will the cart have at the end of the ride?
12,546J
A 1200kg car, travelling at 20m/s, strikes the bumper of another car whose bumper has a spring constant of 1000N/m. How much will the bumper be compressed?
22cm
This US nuclear project really "blew up" near the end of World War II, taking its name from the borough of New York City.
What/Where is Manhattan?