Question

1. If you exert a force of 10.0 N to lift a box a distance of 0.75 m, how much work do you do?
(1 point)0.075 J
7.5 J
10.75 J
75 J

2. If you exert a force of 500 N to walk 4 m up a flight of stairs in 4 s, how much power do you use?
(1 point)31 W
500 W
2,000 W
8,000 W

3. How can you make the work output of a machine greater than the work input?
(1 point)by decreasing friction
by increasing the input force
by increasing the output distance
none of the above

4. A 100-m long ski lift carries skiers from a station at the foot of a slope to a second station 40 m abov

Answer 1

I'm sorry but I dont think I can help you do this. This looks too much like an exam to me. I'd be willing to help if you gave your thoughts about the questions.
Like #3, How could you get Work to increase when you put it through a machine?
Cheers

Answer 2

1. 10.0 N * 0.75 m = 7.5 J
2. 500 N * 4 m / 4 s = 500 W

Answer 3

remember, work done in lifting an object is stored in the form of potential energy
so potential energy = m*g*h = 10*0.75 = 7.5 j

Answer 4

power = work done per unit time
p= w/t
you have 'w' you have 't' , find p

Answer 5

output can never be greater than input, efficiency can be increased but output not, under ideal conditions output= input but can never be greater