The figure shows three forces applied to a trunk that moves leftward by $3\, m$ over a smooth floor. The force magnitudes are $F_1 = 5\, N$,$F_2 = 9\, N$,and $F_3 = 3\, N$. The net work done on the trunk by the three forces is ............... $J$.

$A$ horizontal force of $10 \ N$ is applied on a block of mass $1.5 \ kg$ which is initially at rest on a rough horizontal surface. The work done by the applied force in a time of $6 \ s$ from the beginning of the motion is (Acceleration due to gravity $= 10 \ m/s^2$; the coefficient of kinetic friction between the block and the surface is $0.2$). (in $J$)

An adult weighing $600 \, N$ raises the centre of gravity of his body by $0.25 \, m$ while taking each step of $1 \, m$ length in jogging. If he jogs for $6 \, km$,calculate the energy utilised by him in jogging assuming that there is no energy loss due to friction of ground and air. Assuming that the body of the adult is capable of converting $10 \, \%$ of energy intake in the form of food,calculate the energy equivalents of food that would be required to compensate for the energy utilised for jogging.

If force $\overrightarrow F = 4\hat i + 5\hat j$ and displacement $\overrightarrow s = 3\hat i + 6\hat k$, then the work done is: (in $\text{ J}$)

$A$ body of mass $6\,kg$ is under a force which causes displacement in it given by $S = \frac{t^2}{4}$ metres, where $t$ is time. The work done by the force in $2\,seconds$ is ............... $J$.

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 $,J$)