A bob of mass 0.1 kg hung from the ceiling of a room by a string 2 m long is set into oscillation. The speed of the bob at its mean position is 1 m s^1. What is the trajectory of the bob if the string is cut when the bob is (a) at one of its extreme positions, (b) at its mean position.

A player throws a bail upwards with an initial speed of 29.4 m s^-1 . What are the velocity and acceleration of the ball at the highest point of its motion?

A sound wave travels at a speed of 339 m s^-1 . If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?

A-stone of mass 0.25 kg tied to the end of a string is whirled round in a circle of radius 1.5 m with a speed of 40 rev./min in a horizontal plane. What is the tension in the string? What is the maximum speed with which the stone can be whirled around if the string can withstand a maximum tension of 200. N?

A shell of mass 0.020 kg is fired by a gun of mass 100 kg. If the muzzle speed of the shell is 80 m s-1, what is the recoil speed of the gun?

A bolt of mass 0.3 kg falls from the ceiling of an elevator moving down with an uniform speed of 7 m s^-1 . It hits the floor of the elevator (length of the elevator = 3 m) and does not- rebound. What is the heat produced by the impact? Would your answer be different if the elevator were stationary?

A body is executing SHM. When its displacement from the mean position is 4 cm and 5 cm, the corresponding velocities of the particle are 10cm/s and 8 cm/s. The time period is

A car moving with a speed of 126 kmh^-1 is brought to stop within a distance of 200 m. What is its retardation and how long it takes for the car to stop ?

An object is at a distance of 1 metre from the pole of a concave mirror. Its image is found to be one-third of the size of the object. Find the position of the image, radius of curvature of the mirror and its focal length.

A point particle of mass 0.1kg is excecuting SHM of amplitude 0.1m. When the particle passes through the mean position, its kinetic energy is 8xx10^(-3) J. Obtain the equation of motion of the particle if the initial phase’of oscillation is 45^@ .

A constant force acting on a body of mass 3.0 kg changes its speed from 2.0 m s^-1 to 3.5 m s^-1 in 25 s. The direction of the motion of the body remains unchanged. What is the magnitude and direction of the force?