Question

A particle moving on a straight line ultimately comes to rest. What is the angle between its initial velocity and acceleration?

Answer 1

Answer:

The angle between its initial velocity and acceleration is zero.

Explanation:

Velocity :

Velocity is the changes of the position of the object with time.

It is defined as:

$v = \dfrac{dx}{dt}$

Where,

x = position of the particle

t = time

v = velocity

Acceleration:

Acceleration is the rate of change of the velocity.

It is defined as:

$a = \dfrac{d^2x}{dt^2}=\dfrac{dv}{dt}$

Where, a = acceleration

The velocity and the acceleration are both vector quantity.

So, a particle moving on a straight line ultimately comes to rest.

Then, the angle between its initial velocity  and the acceleration is zero because the velocity and acceleration is same direction.

Hence, The angle between its initial velocity and acceleration is zero.

Answer 2

Answer:

180 degrees or pi

Explanation:

Since the particle decreased its velocity therefore the velocity has to be in opposite direction of acceleration so angle between their direction will be  

180

0

.