Question

lesson 13 work and energy?
I need help on a few questions.... please help!
1. If you perform 10 joules of work lifting a 10-N box from the floor to a shelf, how high is the shelf?
a. 1m
b. 2m
c. 10m
d.100m
2. How can a machine make work easier for you?
a. By decreasing the amount of work you do.
b. By changing the direction of your force.
c. By increasing the work done by the machine.
d. None of the above.
3. How can you make the work output of a machine greater the the work input?
a. By decreasing friction.
b. By increasing the input force.
c. By increasing the output distanc