Equal masses (m each) are attached at the two ends of a string passing over two pulleys. Another mass is attached at the centre of the string. In order that there is no sag in the string, this mass should be

The work done by all the forces (external and internal) on a system equals the change in

A heavy stone is thrown from a cliff of height h with a speed v. The stone will hit the ground with maximum speed if it is thrown

Two bodies of masses m and 4 m are moving with equal kinetic energy. The ratio of their linear momenta is

Two bodies of masses m and 4 m are moving with equal linear momentum. The ratio of their kinetic energies is

The work done by the external forces on a system equals the change in

What is the dimensions of power:

Two ball bearings of mass m each moving in oppsite directions with equal speed v coollide head-on with each other. Predict the outcome of the collision, assuming it to be perfectly elastic.

A body constrained to move along the z-axis of a coordinate system is subject to a constant force F given by F =\((-\hat{i}+\hat{2j}+\hat{3k})\) N, Where \(\hat{i}\), \( \hat{j} \)and \(\hat{k}\) are unit vectors along the x-, y- and z-axis of the system respectively. What is the work done by this force in moving the body a distance of 4 m along the z-axis ?

Calculate the work done by a car against gravity is zero because force of gravity is vertical and motion of car is along a straight horizontal road.

Name the parameter which is a measure of the degree of elasticity of a body.

What is a variable force?

A body of mass 3 kg is under a constant force, which causes a displacement S in metre in it, given by the relation S = \(\frac{1}{3}\) t₂, where t is in an second. Find the work done by the force in 2s.

Draw a graph showing variation of potential energy, kinetic energy and the total energy of a body freely falling on Earth from a height h.

A block of mass m moving with speed v compresses a spring through a distance x before its speed is halved. What is the value of spring constant?

To simulate car accidents, auto manufacturers study the collisions of moving cars with mounted springs of different spring constants. Consider a typical simulation with a car of mass 1000 kg moving with a speed 18.0 km/h on a smooth road and colliding with a horizontally mounted spring of spring constant 5.25 × 10 3 N m^–1 . What is the maximum compression of the spring ?

Estimate the amount of energy released in the nuclear fusion reaction.
₁H² + ₁H² \(\rightarrow\)₂He³ + ₀n¹
Given that M (₁H² ) =2.0141 u,
M (₂He³) =3.0160 u
Mn =1.0087 u, where 1 u =1.1661 \(\times\)10^-27 kg
Express your answer in units of MeV.