Motion in a Pla...

A train is moving along a straight line with a constant acceleration \'a\'. A boy standing in the train throws a ball forward with a speed of 10 m/s, at an angle of 60^o to the horizontal. The boy has to move forward by 1.15 m inside the train to catch the ball back at the initial height. The acceleration of the train in m/s² is

Assertion: In projectile motion, the angle between the instantaneous velocity and acceleration at the highest point is 180^o
Reason: At the highest point, velocity of projectile will be in horizontal only.

Assertion: Two particles of different mass, projected with same velocity at same angles. The maximum height attained by both the particle will be same
Reason: The maximum height of projectile is independent of particle mass.

Assertion: The maximum horizontal range of projectile is proportional to square of velocity
Reason: The maximum horizontal range of projectile is equal to maximum height attained by projectile.

Assertion: A body of mass 1 kg is making 1 rps in a circle of radius 1 m. Centrifugal force acting on it is 4π²N.
Reason: Centrifugal force is given by F = mv²/r

Assertion: A coin is placed on phonogram turn table. The motor is started, coin moves along the moving table.
Reason: The rotating table is providing necessary centripetal force to the coin.

Assertion: The trajectory of projectile is quadratic in y and linear in x.
Reason: y component of trajectory is independent of x-component

Assertion: Two similar trains are moving along the equatorial line with the same speed but in opposite direction. They will exert equal pressure on the rails.
Reason: In uniform circular motion the magnitude of acceleration remains constant but the direction continuously changes.

Assertion: When a body is dropped or thrown horizontally from the same height, it would reach the ground at the same time.
Reason: Horizontal velocity has no effect on the vertical direction

Assertion: When the velocity of projection of a body is made n times, its times of flight becomes n times
Reason: Range of projectile does not depend on the initial velocity of a body.