Final answer:
The magnitude of the horizontal velocity of a football kicked at a 45° angle to the horizontal with an initial velocity of 15 m/s, neglecting air resistance, is approximately 10.61 m/s.
Step-by-step explanation:
To calculate the magnitude of the horizontal velocity of a football kicked at a 45° angle to the horizontal, we can use the initial velocity and trigonometry. The horizontal velocity component (Vx) can be calculated using the cos function, as follows:
Vx = V * cos(θ)
where V is the initial velocity of the ball and θ is the launch angle. Given that the velocity (V) is 15 m/s and the angle (θ) is 45°, we find:
Vx = 15 m/s * cos(45°)
Since cos(45°) = 0.7071 (approximately), the horizontal velocity at the highest point (which remains constant due to the neglect of air resistance) is:
Vx ≈ 15 m/s * 0.7071 ≈ 10.61 m/s.