What is the minimum acceleration with which a person can slide down a rope,if the breaking strength of the rope is $\frac{2}{3}$ of the person's weight?

An $80\, kg$ person is parachuting and is experiencing a downward acceleration of $2.8\, m/s^2$. The mass of the parachute is $5\, kg$. The upward force on the open parachute is ........... $N$ (Take $g = 9.8\, m/s^2$)

An elevator accelerates upwards at a constant rate. $A$ uniform string of length $L$ and mass $m$ supports a small block of mass $M$ that hangs from the ceiling of the elevator. The tension at distance $l$ from the ceiling is $T$. The acceleration of the elevator is

$A$ system of $10$ balls,each of mass $m = 2 \; kg$,is connected via a massless and unstretchable string. The system is allowed to slip over the edge of a smooth table as shown in the figure. Find the tension $T$ in the string between the $7^{th}$ and $8^{th}$ ball when the $6^{th}$ ball just leaves the table. (in $; N$)

$A$ mass of $10 \, g$ is suspended by a string and the entire system is falling with a uniform acceleration of $400 \, cm/s^2$. The tension in the string will be.......... $dyne$ $(g = 980 \, cm/s^2)$.

$A$ car of mass $1250 \ kg$ is moving at $30 \ m/s$. Its engine delivers $30 \ kW$ while the resistive force due to the surface is $750 \ N$. What is the maximum acceleration that can be given to the car in $m/s^2$?