Group 4 Quiz

How much work is done when you lift a 9.0 kg object to 0.50 meters off the ground?

• 42J

• 44.1J

• 4.5J

• 18J

What power output is required of a motor that needs to lift a 450kg elevator car 12 meters in 8.0 seconds?

• 6.615 Watts

• 675 Watts

• 43,200 Watts

• 300 Watts

A student runs up a flight of stairs. which information is not needed to calculate the rate at which the students is doing work against gravity?

• The height of the stairs.

• The length of the flight of stairs.

• The time taken to run up the stairs

• The weight of the students.

What is the standard unit for mechanical advantage?

• Watt

• Joule

• Newton

• It has no unit.

It takes 50 J of work to climb a set of stairs, how fast would you have to climb them to use 5 Watts of power?

• 2 seconds

• 5 seconds

• 9 seconds

• 10 seconds

Using a lever, Rain is able to lift a 10,000 N car off the ground with a force of 1000 N. What is the mechanical advantage of the lever?

• 1

• 10

• 100

• 1000

It is the ratio of the work output to the work input of the machine

• Efficiency

• Wok

• Power

• Mechanical advantage

The mechanical advantage of an inclined plane depends upon its slope and height.

• True

• False

What is the Mechanical advantage of an inclined plane that is 5m long and 2m high?

• 0.4

• 2.5

• 10

• 2

A construction worker uses a board and log as a 1st class lever to lift a heavy rock. If the input arm is 3 meters long and the output arm is 0.75 meters long, what is the mechanical advantage of the lever?

• 3.75

• 2.25

• 4

• 2