A5 kg book rests on a table. how much force is it exerting on the table?
(hint: think about acceleration due to gravity.)

49N

Explanation:

Basically, think of this problem as asking how much the book weighs, as that is all weight is, how much force you exert on whatever surface you're on.

Thus, the force due to gravity Fgrav = mg = 5 * 9.8m/s^2 = 49N.

the answer is kevlar

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