Acar moves from a position 50 m south of the library to a new position 250
m north of the library. this movement takes 15 seconds. what is the velocity
of the car?
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o
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a. 20 m/s north
b. 20 m/s south
c. 13 m/s south
d. 13 m/s north

A. 20 m/s north

Explanation:

The velocity of the car can be  calculated as:

where

d is the displacement

t is the time interval

Taking north as positive direction, the initial position of the car is

(south)

while the final position is

(north)

So, the displacement is

(north)

The time interval for the motion is

t = 15 s

So, the velocity of the car is

(north)

it's a b and

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray