$A$ mass of $100\,kg$ is moved with uniform velocity under the influence of force $F$. Find the force acting on the beam due to the string connected to the ceiling in $N$.

$A$ student calculates the acceleration of $m_1$ in the figure shown as $a_1 = \frac{(m_1 - m_2)g}{m_1 + m_2}$. Which assumption is not required to do this calculation?

An arrangement of a spring,strings,a pulley,and masses is shown in the figure below. The pulley and the strings are massless and $M > m$. The spring is light with spring constant $k$. If the string connecting $m$ to the ground is detached,then immediately after detachment,

The acceleration of the $2\,kg$ block if the free end of the string is pulled with a force of $20\,N$ as shown in the figure is:

$A$ lift is going up. The total mass of the lift and the passenger is $1500\, kg$. The variation in the speed of the lift is as given in the graph. The tension in the rope pulling the lift at $t = 11\, s$ will be ............ $N$.

Three identical blocks of masses $m = 2\; kg$ are pulled by a force $F = 10.2\; N$ with an acceleration of $0.6\; m/s^2$ on a frictionless surface. What is the tension (in $N$) in the string between the blocks $B$ and $C$?