Question

An electric motor and a single-fixed pulley work together to lift a 500 kg crate 50.0 m. How much work was done?

A) 10 J
B) 30,000 J
C) 3,000 J
D) 200,000 J

Answer 1

Answer : Work done, W = 245,000 J

Explanation :

It is given that,

Mass of the system, m = 500 kg

Distance, d = 50 m

According to the definition of work done,
`W=force* displacement`

So, work done to lift the system of electric motor and a pulley is :

`W=mg* h`

`W=500\ kg* 9.8\ m/s^2* 50\ m`

`W=245,000\ J`

Hence, this is the required solution.

Answer 2

Answer: The work done is 245000 J.

Explanation:

The formula for the force due to the weight of the object is as follows;

`F=mg`

Here, m is the mass of the object and g is the acceleration due to gravity.

Put m=500 kg and g=9.8 meter per second.

`F=(500)(9.8)`

`F=4900 N`

The formula for the work done is as follows;

`W=Fs`

Here, F is the force and s is the displacement.

Put F=4900 N and s=50.0 m.

`W=(4900)(50)`

`W=245000 J`

Therefore, the work done is 245000 J.