Question

What is the work required to raise a 10. kg object from the surface of the Earth to a height of 2.0 m?

A. 5.0 J
B. 20. J
C. 2.0 E2 J
D. 2.0 E3 J

Answer 1

(10 kg)(9.8 m/s^2)(2.0 m) = 196 kg m^2/s^2 =~ 200 J
200 J could be written as 2.0 E2 J

Answer 2

Answer: The correct answer is Option C.

Explanation: Work is defined as the product of force and displacement.

Force is defined as the product of mass of the object and acceleration. (here taking acceleration due to gravity).

`W=F.d` ...(1)

`F=mg` ...(2)
`(g=9.8ms^(-2))`

Putting values in equation 2, we get:

`F=10* 9.8=98N`

Now, putting values in Equation 1, we get:

`W=98* 2=196Nm\approx 2* 10^2J` ( Conversion Factor: 1Nm = 1J )

Hence. the correct answer is Option C.