Acar and a heavy truck roll down a hill and reach the bottom at the same speed. compared with the momentum of the truck, the momentum of the car is
a. less. b. the same. c. more. d. none of the above.

A. less

Explanation:

The momentum of an object is directly proportional to it mass and velocity. It is the product of mass and velocity of the object. Given as

So the momentum of car,

Momentum of truck,

We know that, mass of car is less than that of truck and velocity of the two are same. It is implied that, momentum of car will be less than that of truck.

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