Simple Machines and Work

Simple Machines and Work

by Marissa Brown

​Work

​W = F x d

​F = W/d

​D = W/f

Multiple Choice

What formula?
F=10 N
d=5m
W=?

• $$W=f\ \times\ d$$  

• $$F=\frac{W}{d}$$  

• $$d=\frac{W}{F}$$  

Multiple Choice

What formula?
F= 7 N
d= ?
W=9 J

• $$W=f\ \times\ d$$  

• $$F=\frac{W}{d}$$  

• $$d=\frac{W}{F}$$  

Multiple Choice

What formula?
F= ?
d= 5
W=9 J

• $$W=f\ \times\ d$$  

• $$F=\frac{W}{d}$$  

• $$d=\frac{W}{F}$$  

Multiple Choice

A girl applies a horizontal force of 400-N to a box as she slides it across the room. If she moves the box 25-m how much work did she do to the box?

• 0 J

• 400 J

• 10,000 J

• 16 J

Multiple Choice

Solve  F= 100 N d= 10 m W= ?

• 1000 J

• 0.1 J

• 10 J

Multiple Choice

Solve  F= 0.25 N d= 60 m W= ?

• 0.004 J

• 15 J

• 240 J

Multiple Choice

Solve  F= ? d=10 m W=20 J

• 200 N

• 0.5 N

• 2 N

Multiple Choice

Solve  F= 40 N d= ? W= 5 J

• 200 m

• 0.125 m

• 8 m

Multiple Choice

Solve  F= 50 N d= 5 m W= ?

• 250 J

• 0.1 J

• 10 J

Multiple Choice

Solve  F= ? d= 25m W=100 J

• 4 N

• 0.25 N

• 2500 N

Multiple Choice

How much work is produced when 350 N is used to move a car 5 m (W=Fd)?

• 70 J
• 1750 J
• 355 J
• 175 J

Multiple Choice

Which of the following is an example of work being done?

• Teacher sitting in a chair
• Book resting on desk
• Keys hanging from a key chain
• A ball being rolled on the floor

Multiple Choice

Is this an example of work? 
A waiter carries a tray full of meals above his head by one arm straight across the room at constant speed. 

• True
• False

Multiple Choice

Is this an example of work? 
A rocket accelerates through space.

• True
• False

Multiple Choice

What is effort (input) force?

• the force one exerts on a machine

• the force which an effort force must overcome in order to do work on an object via a simple machine.

• the force the machine exerts on a object

• the output work times the input distance

Multiple Choice

A box of weight W is lifted by a force F using a lever as shown below.

What is the mechanical advantage of the lever (MA=Input Distance/Output Distance)?

• 0.5

• 2

• 3

• 6

Multiple Choice

Using a lever, Joe is able to lift a 10,000 N car off of the ground with a force of 1000 N. What is the mechanical advantage of the lever (MA=Output Force/Input Force)?

• 1

• 10

• 100

• 1000

Multiple Choice

if a load of a lever is 100 newtons and the force you apply is 20 newtons, what is your mechanical advantage?

• 120 N
• 5 N
• 2000 N
• 80 N

Fill in the Blank

What is the MA of 1 fixed pulleys and 1 moveable pulleys?

Multiple Choice

The mechanical advantage of this inclined plane is...(MA=Resistance Force/Effort Force)

• 2.4

• 3.4

• 4.4

Multiple Choice

Simple machines like inclined planes, have what effect on work?

• Decrease the amount of force needed

• Increase the amount of force needed

• Simple machines have no effect on force