2. if you exert a force of 10.0 n to lift a box a distance of 0.9 m, how much work have you done?
0.1 j
9.0 j
10.9 j
90.0 j
3. the power of a machine measures
its rate of doing work.
its strength.
the force it produces.
the work it does.
4. if you exert a force of 700 n to walk 6 m up a flight of stairs in 6 s, how much power do you use?
19 w
25,200 w
700 w
4,200 w
5. a 750-w motor might also be rated as a
0.5-horsepower motor.
1-horsepower motor.
2-horsepower motor.
10-horsepower motor.

Answer :

(2) The work done is, 9.0 J

(3) The power of a machine measures  its rate of doing work.

(4) The power used, 700 W

(5) A 750-W motor might also be rated as a  1-horsepower motor.

Solution for part (2) :

Formula used :

where,

W = work done = ?

F = applied force = 10 N

d = displacement = 0.9 m

Now put all the given values in the above formula, we get the work done.

Therefore, the work done is, 9.0 J

Explanation for part (3) :

Power : it measures the rate of doing work by time.

Formula for power is,

Solution for part (4) :

Formula used :

where,

W = work done

F = applied force = 700 N

d = displacement = 6 m

t = time taken = 6 s

Now put all the given values in the above formula, we get the work done.

Therefore, the power used, 700 W

Solution for part (5) :

As, 746 watt is equal to 1 horsepower

So, 750 watt is equal to

Therefore, a 750-W motor might also be rated as a  1-horsepower motor.