Question

Calculate the work done by a car against gravity in moving along a straight horizontal road. The mass of the car is $400kg$ and the distance moved is $2m$.

Answer 1

Definition: Work; work done is product of the component of the force in the direction of the displacement and magnitude of this displacement.

Formula used: $W=Fscos\theta$

Given, car is moving on horizontal straight road, so displacement of the car is along horizontal.

Gravitational force is acts on the car in downward direction.

therefore, angle between the gravitational force and displacement is ${90}^{\circ }$ Work done by the gravitational force,

$W=\overrightarrow{F}.\overrightarrow{S}=Fscos\theta$

$W=Fscos\left({90}^{\circ }\right)$

$W=0$

Final answer: Zero