The time taken by a force of $2 \ N$ to produce a change of momentum of $0.4 \ kg \ m \ s^{-1}$ in a body is: (in $s$)

An object of mass $2 \, kg$ is placed at rest in a frame $S_1$ moving with velocity $10 \hat{i} + 5 \hat{j} \, m/s$ and having acceleration $5 \hat{i} + 10 \hat{j} \, m/s^2$. The object is also seen by an observer standing in a frame $S_2$ moving with velocity $5 \hat{i} + 10 \hat{j} \, m/s$. Calculate the net force acting on the object with respect to the $S_1$ frame.

The force required to stop a body of mass $10 \,kg$ moving along a straight line path with a velocity of $10 \,ms^{-1}$ in a time of $10 \,s$ is (in $\,N$)

$A$ force vector applied on a mass is represented as $\vec F = 6\hat i - 8\hat j + 10\hat k$ and accelerates the body with $1\;m/s^2$. What will be the mass of the body in $kg$?

$A$ body,under the action of a force $\vec F = 6\hat i - 8\hat j + 10\hat k$,acquires an acceleration of $1\, m/s^2$. The mass of this body must be

$A$ constant retarding force of $50\; N$ is applied to a body of mass $20\; kg$ moving initially with a speed of $15\; m/s$. How long (in $sec$) does the body take to stop?