Find the force $F$ required on the cart so that the $2 \ kg$ and $1 \ kg$ blocks remain stationary relative to the cart.

$A$ person sitting inside an elevator performs a weighing experiment with an object of mass $50 \ kg$. Suppose that the variation of the height $y$ (in $m$) of the elevator,from the ground,with time $t$ (in $s$) is given by $y = 8[1 + \sin(\frac{2 \pi t}{T})]$,where $T = 40 \pi \ s$. Taking acceleration due to gravity,$g = 10 \ m/s^2$,the maximum variation of the object's weight (in $N$) as observed in the experiment is $.....$ .

An object dropped in a stationary lift takes time $t_1$ to reach the floor. It takes time $t_2$ when the lift is moving up with constant acceleration. Then

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 pseudo force acting on the object. Which frame is responsible for this force?

$A$ ball is suspended on a thread from the ceiling of a car. The brakes are applied and the speed of the car changes from $5 \, m/s$ to $5/3 \, m/s$ during a time interval of $3 \, s$. Find the angle $\theta$ that the thread will deviate from the vertical.

$A$ thief stole a box full of valuable articles of weight $W$ and while carrying it on his back,he jumped down a wall of height $h$ from the ground. Before he reached the ground,he experienced a load of: