$A$ force separately produces accelerations of $18 \ m/s^2$, $9 \ m/s^2$, and $6 \ m/s^2$ in three bodies of masses $P$, $Q$, and $R$ respectively. If the same force is applied on a body of mass $P+Q+R$, then the acceleration of that body is: (in $m/s^2$)

$A$ force of $5 \, N$ acts on a body of weight $9.8 \, N$. What is the acceleration produced in $m/s^2$?

$A$ 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 velocity of an object of mass $2 \ kg$ is given by $v = (8t \hat{i} + 3t^2 \hat{j}) \ m/s$, where $t$ is time in seconds. What will be the direction of the net force on the object relative to the positive direction of the $X$-axis, at the instant when its magnitude is $20 \ N$?

$A$ 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

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