When a solid uniform sphere is spinning about an axis of rotation through its center, its rotational kinetic energy is K and moment of inertia I = ⅖ MR2. A second solid sphere having twice the mass and twice the diameter of the first one is spinning about an axis through its center and has a twice the angular velocity of the first sphere. The rotational Kinetic energy of the second sphere is: 8K
4K
32K
2K
K

uh.

Explanation:

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