Final answer:
The final velocity of a 118 kg rugby player after colliding with a goalpost can be found using the impulse-momentum theorem, which considers the force of impact and the time over which it is applied. By multiplying the backward force by the time of impact and then dividing by the player's mass, you can find the change in velocity. This change is subtracted from the initial velocity to get the final velocity.
Step-by-step explanation:
To calculate the final velocity of a 118 kg rugby player who collides with a goalpost, we use the principles of physics, specifically Newton's second law of motion and the impulse-momentum theorem. First, we must calculate the change in momentum (impulse) the player experiences due to the collision. The impulse can be determined by multiplying the force experienced by the player by the duration of the force's application.
The force applied is 17700 N in the opposite direction of the player's initial motion, and it is applied for 5.50 × 10-2s. The impulse is therefore:
Impulse = Force × Time = 17700 N × 5.50 × 10-2 s
Subsequently, we can determine the change in velocity by dividing the impulse by the mass of the player.
Change in velocity (Δv) = Impulse / Mass = (17700 N × 5.50 × 10-2 s) / 118 kg
After calculating the change in velocity, we subtract it from the player's initial velocity to find the final velocity.
Final velocity = Initial velocity - Δv
Note that the player's final velocity will be opposite in direction to their initial velocity due to the applied force being backward.