Motion in a Pla...

Assertion: Improper banking of roads causes wear and tear of tyres.
Reason: The necessary centripetal force is provided by the force of friction between the tyres and the road.

Assertion: When range of a projectile is maximum, its angle of projection may be 45^o or 135^o.
Reason: Whether θ is 45^o or 135^o, value of range remains the same, only the sign changes.

Assertion: In order to hit a target, a man should point his rifle in the same direction as target.
Reason: The horizontal range of the bullet is dependent on the angle of projectile with horizontal direction.

Assertion: When an automobile while going too fast around a curve overturns, its inner wheels leave the ground first.
Reason: For a safe turn the velocity of automobile should be less than the value of safe limit velocity.

Assertion: During a turn, the value of centripetal force should be less than the limiting frictional force.
Reason: The centripetal force is provided by the frictional force between the tyres and the road.

Assertion: When a vehicle takes a turn on the road, it travels along a nearly circular path.
Reason: In circular motion, velocity of vehicle remains same.

Assertion: As the frictional force increases, the safe velocity limit for taking a turn on an unbanked road also increases
Reason: Banking of roads will increase the value of limiting velocity.

Assertion: If both the speed of a body and radius of its circular path are doubles, then centripetal force also gets doubled
Reason: Centripetal force is directly proportional to both speed of a body and radius of circular path.

Assertion: In circular motion, the centripetal and centrifugal force acting in opposite direction balance each other
Reason: Centripetal and centrifugal forces don\'t act at the same time.

Assertion: A safe turn by a cyclist should neither be fast nor sharp.
Reason: The bending angle from the vertical would decrease with increase in velocity.