A toy car, initially travelling in a straight line at 30.0 cm/s, slows down with a constant linear acceleration of 3.0 cm/s2. How much time passes before the toy car comes to a halt?

The toy car stops after 10 seconds.

Explanation:

Constant Acceleration Motion

It's a type of motion in which the velocity of an object changes uniformly at a rate called acceleration.

Being a the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

The toy car moves at vo=30 cm/s and decelerates at . Note the negative sign of the acceleration that indicates the speed is decreasing over time.

We need to calculate the time needed for the toy car to stop vf=0.

To find the time, we solve [1] for t:

Since all the units of speed and acceleration are in centimeters, we don't need to convert to meters

The toy car stops after 10 seconds.

e

explanation:

there is no change in the electric potential energy as it is in rest on both conditions.

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