g Tether ball is a game children play in which a ball hangs from a rope attached to the top of a tall pole. The children hit the ball, causing it to swing around the pole. What is the total initial acceleration of a tether ball on a 2.0 m rope whose angular velocity changes from 13 rad/s to 7.0 rad/s in 15 s

Respuesta :

Answer:

a = -0.8 m/s²

Here, negative sign indicates that the acceleration has opposite direction to the direction of motion.

Explanation:

First we find the angular acceleration of the ball from the following formula:

α = (ωf - ωi)/t

where,

α = angular acceleration = ?

ωf = final angular velocity = 7 rad/s

ωi = initial angular velocity = 13 rad/s

t = Time taken = 15 s

Therefore,

α = (7 rad/s - 13 rad/s)/15 s

α = - 0.4 rad/s

negative sign shows that acceleration is in opposite direction to the direction of motion.

Now, for the linear acceleration, we use the formula:

a = rα

where,

a = linear acceleration = ?

r = radius of circular path = length of rope = 2 m

therefore,

a = (2 m)(- 0.4 rad/s²)

a = -0.8 m/s²

Here, negative sign indicates that the acceleration has opposite direction to the direction of motion.