Question

A golf ball of a diameter 1.68 inches rolls a distance of 4m in a straight line.How many times does a ball rotate completely ? ( 1 inch = 2.54cm)

Answer 1

Answer:

Number of rotations of the ball nearly = 30 rotations

Step-by-step explanation:

In the question,

Diameter of golf ball, d = 1.68 inches

Distance rolled, s = 4 m

Now,

1 inch = 2.54 cm

So,

Diameter of golf ball, d = 1.68 x 2.54 = 4.2672 cm

Radius, r = 2.1336 cm

Now,

Circumference of circle = 2πr

So,

Circumference of Golf Ball, C = 2×π×2.1336

Circumference, C = 13.405

So,

Number of rotations is given by,

\begin{gathered}Number \ of\ rotations=\frac{Distance\ travelled\ by\ ball}{Circumference\ of\ ball}\\N=\frac{s}{C}\\So,\\N=\frac{4\times 100}{13.405}\\N=29.83 \\\end{gathered}

Number of rotations=

Circumference of ball

Distance travelled by ball

N=

C

s

So,

N=

13.405

4×100

N=29.83

Therefore, the number of rotations by the ball is nearly,

N = 30 rotations