Work and Energy

Not a type of energy:

a) Chemicalb) Electricalc) Mechanicald) Political

By definition, Mechanical Energy means “the energy required to:”

a) Boil waterb) Fix a carc) Move an objectd) Heat a home

Two types of mechanical energy:

a) Nuclear and Electricalb) Electrical and Kineticc) Kinetic and Gravitationald) Thermal and Electrical

The General Equation for all Mechanical Work is:

a) W = Fxdb) W = mghc) W = ½ mv2

d) W = mg

Work can be done by:

a) Boiling waterb) Raising a book onto a shelfc) Accelerating a massd) All of the above

I can do work by:

a) dropping a book.b) Holding a heavy bag of groceriesc) Skateboarding at a constant speed.d) Doing push-ups

I can do work by:

a) Writing a letterb) Jogging to schoolc) Climbing stairsd) Building a fort

The Earth does work when:

a) I lift a book on to a shelfb) I am tobogganing down a hillc) I drive my card) I skate along the canal

A ramp has an IMA of 5. This means:

a) It takes a force of 5N to push a 1N weight up the ramp.

b) It takes a force of 1N to push a 5N weight up the ramp.

c) If it takes 5J of energy to lift an object without the ramp, it will only take 1J of energy using the ramp.

d) If it takes 1J of energy to lift an object without the ramp, it will take 5J of energy using the ramp.

A simple machine:

a) Allows us to do the same work with less energy.

b) Allows us to do the same work with more energy.

c) Allows us to do the same work with less force.

d) Allows us to do the same work with more force.

A frictionless pulley system has an IMA of 5. Which is True:

a) To lift a mass up 5m, I need to pull 1m of ropeb) To lift a mass up 1m, I need to pull 5m of ropec) To lift a 1N weight, I need a force of 5N.d) None of the above

A pulleys system has friction. Which of the following is FALSE:

a) The AMA of the system is less than the IMA of the system.

b) The efficiency of the system is less than 100%c) It will take more force to lift the weight using

the pulley system than without the pulley system.

d) It will take more energy to lift the weight using the pulley system than without the pulley system

To pull a nail out of a block of wood, you need a lever with a high MA because:

a) You need a lot of force to move a small mass.b) The nail moves a greater distance than your

hand does.c) A small force from your hand will be

converted into a larger force pulling the nail.d) You want to pull the nail using less work.

This machine has an IMA less than 1.0:

a) Crowbarb) Baseball batc) Rampd) Hole punch

Beaker tongs have an IMA of 1.0. The tongs are used because:

a) They allow us to grip the beaker without burning our fingers

b) They reduce the force on the beaker, making it less likely to break.

c) They increase the force on the beaker, making it less likely to slip.

d) They allow us to lift a heavy beaker with less force.

A machine has an efficiency of 80%. This means:

a) The machine is frictionlessb) The AMA is less than the IMAc) The IMA is less than the AMAd) Applied force is more than the load force

A skateboarder is gliding down a hill. Halfway down the hill, the

total energy of the skateboarder is: a) Egb) Ekc) Ek + Egd) mcΔT

A skateboarder sits at rest atop a ramp. The speed of the skateboarder halfway down the

ramp is calculated. The LOC of energy says:a) Ek = Eg’b) Ek + Eg = Ek’ + Eg’c) Ek = Eg’ + Ek’d) Eg = Eg’ + Ek’