Question

When a wheel is rotated through an angle of 21◦ , a point on the circumference travels through an arc length of 2.1 m. When the wheel is rotated through angles of 21 rad and 21 rev, the same point travels through arc lengths of 120 m and 7.6×102 m, respectively. What is the radius of the wheel? Answer in units of m.

Answer 1

Answer:

R = 5.73 m

Explanation:

For an angle of rotation through 21 degree we know that

arc length is given as

$angle \times Radius = Arc$

now we know that

Arc = 2.1 m

Angle = 21 degree

$Angle = 21\times \frac{\pi}{180}$

so now we have

$21\times \frac{\pi}{180} = \frac{2.1}{R}$

$R = \frac{2.1 \times 180}{21 \times \pi}$

$R = 5.73 m$