Work in Physical Science

Multiple Choice

Which statement about the actual mechanical advantage of a machine is true?

• The actual mechanical advantage is greater than one if the input force is greater than the output force

• The actual mechanical advantage of a machine is greater than its ideal mechanical advantage when the output force is greater than the input force

• The actual mechanical advantage of a machine is always less than its ideal mechanical advantage

• The actual mechanical advantage of a machine is never affected by friction

Multiple Choice

If a lever raises a large rock 0.1 meters when the other end of the lever moves downward 2 meters, what is the ideal mechanical advantage of the lever

• 0.05

• .5

• 2

• 20

Multiple Choice

A machine is used to accomplish 300 J of work. If the efficiency of the machine is 60 percent, what is the necessary work input?

• 180 J

• 360 J

• 500 J

• 750 J