# Motion and Force

## The trajectory (or path) of a projectile is

A.straight line B.parabola C.hyperbola D.circle

## At which angle the range of the projectile is maximum

A.45? B.60? C.30? D.none

## The force beared by a wall on which water strikes normally at a speed of 10m/sec and at a discharge of 0.0001m3/sec is.

A.1 N B.10 N C.100 N D.none

## Time rate of change of momentum is equal to

A.force B.impulse C.velocity D.both (a) and (c)

## The range of the projectile at 30? and 60? are

A.equal to 45? B.equal to 90? C.equal to each other D.none of the above

## Why Ballistic missile fails in some circumstances of precision.

A.due to their shape B.due to air resistance C.due to angle of projection D.att of these

## Taking off rocket can be explained by

A.1st law of motion B.2nd law of motion C.Law of conservation of momentum D.law of conservation of energy

## Which of the following is not an example of projectile motion.

A.a gas filled ballon B.bullet fired from gun C.a football kicked D.a base ball shot

## What is the angle of projection for which the range and maximum height become equal?

A.tan-1 1/4 B.tan-1 4 C.tan-1 1/2 D.tan-1 2

## The thrust on the rocket in the absence of gravitational force of attraction is

A.constant B.not constant C.constant if the rate of ejected gases is constant D.constant for short range rocket.