To find the angular speed imparted to the ball, we can use the relationship between linear speed, angular speed, and the radius of the ball. The formula we will use is:
Understanding the Relationship
The linear speed (v) of an object is related to its angular speed (ω) by the equation:
v = ω * r
Where:
- v is the linear speed in meters per second (m/s).
- ω is the angular speed in radians per second (rad/s).
- r is the radius of the ball in meters (m).
Converting Units
First, we need to convert the speed of the ball from kilometers per hour (km/h) to meters per second (m/s). The conversion factor is:
1 km/h = 1/3.6 m/s
So, for a speed of 145 km/h:
v = 145 km/h * (1/3.6 m/s per km/h) ≈ 40.28 m/s
Finding the Radius
Next, we need to determine the radius of the ball. The perimeter (circumference) of the ball is given as 22.4 cm. The relationship between the circumference (C) and the radius (r) is:
C = 2 * π * r
Rearranging this to find the radius gives us:
r = C / (2 * π)
Substituting the given circumference:
r = 22.4 cm / (2 * π) ≈ 3.57 cm
Now, converting this to meters:
r ≈ 0.0357 m
Calculating Angular Speed
Now that we have both the linear speed and the radius, we can find the angular speed using the rearranged formula:
ω = v / r
Substituting the values we have:
ω = 40.28 m/s / 0.0357 m ≈ 1126.5 rad/s
Considering the Spin Ratio
The spin ratio of 0.1 indicates how much of the linear speed contributes to the spin of the ball. To find the effective angular speed imparted to the ball, we multiply the calculated angular speed by the spin ratio:
Effective Angular Speed = ω * Spin Ratio
Effective Angular Speed ≈ 1126.5 rad/s * 0.1 ≈ 112.65 rad/s
Final Result
Thus, the approximate angular speed imparted to the ball is about 112.65 rad/s. This value reflects how quickly the ball is spinning as it travels through the air, influenced by both its linear speed and the spin ratio.