Laws of Motion

A life can move upward or downward. A light inextensible string fixed from the ceiling of the lift with a  frictionless pulley and tension in string $${ T }_{ 1 }$$. Two masses of $${ m }_{ 1 }$$ and $${ m }_{ 2 }$$ are connected with inextensible light string and tension in this string $${ T }_{ 2 }$$ as shown in the figure. Read the question carefully and answer.
If $${ m }_{ 1 }+{ m }_{ 2 }=m$$ and lift is moving with a constant velocity then value of $${ T }_{ 1 }$$
In the first second of its flight, rocket ejects 1/60 of its mass with a velocity of 2400 m/s. The acceleration of the rocket is :
A block of mass $$m$$ is pulled along a horizontal surface by a horizontal rope of mass $$1 kg$$. A force of $$15 N$$ is applied at the free end of the rope. The force exerted by the block on the rope is $$13.5 N$$. the mass $$m$$ of the block is:
One end of an elastic string is attached to a block of mass m and the other end is held keeping the string relaxed and vertical. Relaxed length of string is $$l_0$$ and there is a mark P at height $$08l_0$$ from the lower end. Now the upper end is slowly raised. When the block leaves the contact from ground, the mark P is $$0.2l_0$$ above the initial position of P. Expression for the work done by the force applied by the hand is?
A block A has a velocity of 0.6 m/s to the right,determ the velocity of cylinder B.