When will a body of mass $20 \ kg$ moving at $15 \ m s^{-1}$,subjected to a retarding force of $100 \ N$,come to rest (in $s$)?

An army vehicle of mass $1000\, kg$ is moving with a velocity of $10\, m/s$. It is acted upon by a forward force of $1000\, N$ due to the engine and a retarding force of $500\, N$ due to friction. What will be its velocity after $10\, s$ (in $, m/s$)?

$A$ body under the action of a force $\vec{F} = 6\hat{i} - 8\hat{j} \text{ N}$ acquires an acceleration of $5 \text{ m s}^{-2}$. The mass of the body is ........ $\text{kg}$.

$A$ boy pushes a box of mass $2 \, kg$ with a force $\overrightarrow{F} = (20 \hat{i} + 10 \hat{j}) \, N$ on a frictionless surface. If the box was initially at rest,then the displacement along the $x$-axis after $10 \, s$ is ........... $m$.

$A$ force $(2 \hat{i} + \hat{j} - \hat{k}) \text{ N}$ acts on a body, which is initially at rest. At the end of $20 \text{ s}$, the velocity of the body is $(4 \hat{i} + 2 \hat{j} - 2 \hat{k}) \text{ ms}^{-1}$. The mass of the body is: (in $\text{ kg}$)

$A$ body of mass $5\, kg$ starts from the origin with an initial velocity $\vec{u} = 30\hat{i} + 40\hat{j}\,m/s$. If a constant force $\vec{F} = -(\hat{i} + 5\hat{j})\,N$ acts on the body,the time in which the $y$-component of the velocity becomes zero is ......... $s$.