Question

A coin completes 18 spins in 12 seconds. The centripetal acceleration of the edge of the coin is 2.2 m/s2. The radius of the coin is m.

Answer 1

Answer: 0.025 m or 2.5m

Explanation:

The number of spins given in 12 seconds = 18

So the number of spins in 1 second will be

= 18 / 12 = 1.5rps

The above result is the frequency because it is the number of spins in one second

Let f be frequency

f = 1.5 rps

Using centripetal acceleration given

Ca = 2.2 m/s^2

m is the radius of the given coin

Using the formula

Centripetal acceleration, = m x w^2

Knowing that w = 2πf

2.2 = m x ( 2 x 3.14 x 1.5) ^2

2.2 = m x 88.7364

m = 0.025 m

Answer 2

Answer:

2.5 cm

Explanation:

Number of spins in 12 seconds = 18

Number of spins in 1 second = 18 / 12 = 1.5

Number of spins in one second is called frequency.

f = 1.5 rps

ac = 2.2 m/s^2

Let r be the radius of coin

Centripetal acceleration, ac = r x w^2

2.2 = r x ( 2 x 3.14 x 1.5) ^2

2.2 = r x 88.7364

r = 0.025 m = 2.5 cm