A roller coaster car moves around a vertical circle. At the bottom of the circle, the car experiences four times as much radial (centripetal) acceleration as at the top of the circle. Compared to its speed at the top of the circle, the speed of the car at the bottom of the circle is:

A. four times as great.
B. 16 times as great
C. √2 times as great
D. twice as great
E. 2√2 times as great.

The speed of the car at the bottom of the circle is twice as its speed at the top of the circle.

Explanation:

It is given that, at the bottom of the circle, the car experiences four times as much radial (centripetal) acceleration as at the top of the circle such that :

The centripetal acceleration is given by :

Let are the speed of the roller coaster car at bottom and at top respectively.

.

So, the speed of the car at the bottom of the circle is twice as its speed at the top of the circle. Hence, the correct option is (D).

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.