$A$ body of mass $2 \, kg$ is moving with a velocity $8 \, m/s$ on a smooth surface. If it is to be brought to rest in $4 \, seconds$,then the force to be applied is ......... $N$.

$A$ force on an object of mass $100\, g$ is $(10 \hat{i}+5 \hat{j})\ N$. The position of that object at $t= 2\ s$ is $(a \hat{i}+b \hat{j})\, m$ after starting from rest. The value of $\frac{a}{b}$ will be..........

The driver of a three-wheeler moving with a speed of $36\; km/h$ sees a child standing in the middle of the road and brings his vehicle to rest in $4.0\; s$ just in time to save the child. What is the average retarding force (in $N$) on the vehicle? The mass of the three-wheeler is $400\; kg$ and the mass of the driver is $65\; kg$.

$A$ force of $6 \; N$ acts on a body at rest and of mass $1 \; kg$. During this time,the body attains a velocity of $30 \; m/s$. The time for which the force acts on the body is ..... $seconds$.

$A$ car of mass $1500 \,kg$ is moving with $20 \,ms^{-1}$ velocity. If the brakes are applied,it comes to rest in $5 \,s$. The retarding force is: (in $\,N$)

$A$ body of mass $1.5 \ kg$ is moving towards south with a uniform velocity of $8 \ ms^{-1}$. $A$ force of $6 \ N$ is applied to the body towards east. The displacement of the body $3 \ s$ after the application of the force is (in $m$)