A1.99 kg ball is attached to a ceiling by a 1.35 m long string. the height of the room is 3.27 m. the acceleration of gravity is 9.81 m/s 2 . what is the gravitational potential energy associated with the ball relative to a) the ceiling? answer in units of j.

-26.35 J

Explanation:

a) Since the ball is hanging on a 1.35m string from the ceiling, the balls height with respect to the ceiling would be -1.35m. It's negative because the ball is below the ceiling.

Let g = 9.81m/s2

Gravitational potential energy of the ball relative to the ceiling would be the product of its mass and its height relative to the ceiling and its gravitational constant g

E = mgh = 1.99 * 9.81 * (-1.35) = -26.35 J

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s