Question

if radius of a circle in which an object is moving at constant speed is doubled and the mass of the object is also doubled. the resulted centripetal force will be?
A. one quarter as great as before
B. one half as grid as before
C. remain constant
D. twice as great as before
E. four times as great as before

Answer 1

Answer on Question #43213, Physics, Mechanics | Kinematics | Dynamics

If radius of a circle in which an object is moving at constant speed is doubled and the mass of the object is also doubled. The resulted centripetal force will be?

A. one quarter as great as before

B. one half as grid as before

C. remain constant

D. twice as great as before

E. four times as great as before

Solution:

Any motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path. This force is called the centripetal force which means "center seeking" force. The force has the magnitude

$$F_{centripetal} = m \frac{v^2}{r}$$

Thus, if $m_2 = 2m_1$ and $r_2 = 2r_1$

$$\frac{F_2}{F_1} = \frac{m_2 r_1}{m_1 r_2} = \frac{2 m_1 r_1}{m_1 2 r_1} = 1$$

Answer: C. remain constant

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