1. A cart of mass 4 kg moves at a speed of 10 m/s to the right when it encounters a horizontal spring of spring constant 250 N/m. The maximum potential energy stored the spring in bringing the cart to rest is (A) 80 J (B) 200 J (C) 280 J (D) 400 J
2. For the same car and spring as the previous problem, what is the maximum compression distance of the spring?
(A) 1.26 m (B) 1.6 m (C) 2.5 m (D) 8 m

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

prndulum needs thread, weight clock to time swings

explanation:

wheres the pic