Question

A box with a mass of 7 kilograms is pushed up a ramp to a height of 5 meters. what is the work done against the force of gravity? assume the ramp has negligible friction.

Answer 1

Answer: The work done by the ramp against the force of gravity is -343 J

Explanation:

Work is defined as the force that is causing the movement or displacement of an object.

Mathematically,

$W=F\times d$

We know that:

$F=m\times g$

where,

W = work done by the ramp = ?

m = mass of the box = 7 kg

g = acceleration due to gravity = $-9.8m/s^2$    (Negative sign appears because it is acting against the gravity)

d = displacement = 5 m

Putting values in above equation, we get:

$W=7kg\times (-9.8m/s^2)\times 5m\\\\W=-343J$

Hence, the work done by the ramp against the force of gravity is -343 J

Answer 2

So work done = mgh = 7×10×5 = 350 joules

so answer is 350 joules !!