When kicking a soccer ball (0.35kg), the time of contact is usually about 5ms. What average kicking force would be required to attain a ball velocity of 110 km/hr if the ball is initially at rest?
V=110km/h = 110,000m/3600s = 30.56 m/s.
a=(V-Vo)/t = (30.56-0)/0.005=6111 m/s^2.
F = m*a = 0.35 * 6111 = 2139 N.
To determine the average kicking force required to attain a ball velocity of 110 km/hr, we can use the principles of Newton's laws of motion and the concept of impulse. The impulse experienced by an object is defined as the product of the average force applied to it and the time of contact.
First, we need to convert the velocity from km/hr to m/s, as the SI unit system is generally used in physics calculations. We know that 1 km/hr is equal to 0.2778 m/s, so 110 km/hr is equal to:
110 km/hr * (0.2778 m/s / 1 km/hr) = 30.56 m/s
Next, we calculate the impulse by multiplying the mass of the ball (0.35 kg) by the change in velocity (30.56 m/s), as any change in velocity implies an impulse has been applied.
impulse = mass * change in velocity
= 0.35 kg * 30.56 m/s
= 10.69 kg⋅m/s
Now, we need to find the average kicking force by dividing the impulse by the duration of contact:
average force = impulse / time of contact
= 10.69 kg⋅m/s / 0.005 s
= 2138 N
Therefore, an average kicking force of 2138 Newtons would be required to attain a ball velocity of 110 km/hr, assuming the ball is initially at rest and the time of contact is 5 milliseconds.