Answer:
180 m/s
Explanation:
The centripetal acceleration a for an object on a circular orbit with radius r and velocity v is given by:

Solving the equation for velocity:

How far it moves over a certain period of time, but unlike the term "speed" velocity is a vector quantity and tells you the direction of an object (speed is also distance over time just without a direction). This means an object can have negative velocity, but it can't have negative speed.
Answer:
(a) Relative speed of Sam = -7 mph
(b) Relative speed of George = 7 mph
Explanation:
We have given speed of Sam 65 mph in north direction.
And speed of George is 72 mph also in north direction
We have find the relative velocity of both Sam and George
(a) Speed of Sam relative to George = speed of Sam - speed of George = 65 -72 = -7 mph
(b) Speed of George with respect to Sam = speed of George - speed of Sam = 72-65 = 7 mph