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

$A$ cyclist comes to a skidding stop in $10 \,m$. During this process,the force on the cycle due to the road is $200 \,N$ and is directly opposite to the motion. How much work does the road do on the cycle?

Work done

If work is done by a body against a force,is the work considered positive or negative?

Force acting on a particle moving in a straight line varies with the velocity of the particle as $F = \frac{K}{v}$,where $K$ is a constant. The work done by this force in time $t$ is

$A$ particle moves in the $x-y$ plane under the action of a force,$F = K \left[ \frac{x}{(x^2+y^2)^{3/2}} \hat{i} + \frac{y}{(x^2+y^2)^{3/2}} \hat{j} \right]$,where $K$ is a constant. The work done by the force when the particle moves from $(0, a)$ to $(a, 0)$ along a circular path of radius $a$ about the origin is: