Question

A simple pendulum having a bob of mass 'm' is suspended from the ceiling of a car used in a stunt film shooting. The car moves up along an inclined cliff at a speed v and makes a jump to leave the cliff and lands at some distance. Let R be the maximum height of the car from the top of the cliff. The tension in the string when the car is in air is
(a) mg
(b) mg-mv²/r
(c) mg+mv²/r
(d) zero

Answer 1

Answer ⇒Zero.

Explanation ⇒ Since the Simple Pendulum is hanged in the car. f the car will jump in the air and fall freely then this will be like a Projectile. Also, If we will go in the Non inertial Frame of the Reference, we need to apply the Pseudo Force, which wwill be equal to the mg upwards.

Now, this mg will balances the weight of the body, and the tension in the string will be given by,

T + mg = mg.

⇒ T = 0.

Hence, the Tension in the string will be zero.

Hope it helps.

Answer 2

Explanation:

acceleration of car is "g" so

g(eff) = g - a