A ball is moving with velocity 5 m/s in a direction which makes an angle of 30° with horizontal (i. e. with positive x-direction). This ball hits a vertical wall and gets reflected in a direction which makes an angle of 60° with the vertical (i. e. with positive y-direction) and moves with the same magnitude i. e. 5 m/s: a. Find components of the initial and reflected velocities.
b. Show the vector representing the change in velocity of the ball.
c. Find the magnitude of the change in velocity.

Explanation:

(a)

From the given information:

The initial velocity = 5 m/s

The direction of the angle θ = 30°

Therefore, the component along the x-axis =

The component along the y-axis =

To find the final velocity( reflected velocity)

using the same magnitude

The angle from the x-axis can be

= 150°

Thus, the component along the x-axis =

The component along the y-axis =

(b)

The velocity can be written as in vector form.

 ----  (1)

The reflected velocity in vector form can be computed as:

 --- (2)

The change in velocity =

(c)

The magnitude of change in velocity =

= 8.66 m/s

when insulating materials rub against each other, they may become electrically charged . electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. the material that gains electrons becomes negatively charged. the material that loses electrons is left with a positive charge.