The range of a projectile fired at an angle with the horizontal and with an initial velocity of feet per second is where r is measured in feet. A golfer strikes a golfball at 115 feet per second. Ignoring the effects of air resistence, at what angle must the golfer hit the ball so that it travels 120 feet? (Round answer to nearest angle.) Question 13 options:

θ = 8.50°

To the nearest angle

θ = 9.0°

the golfer must hit the ball at angle 9° so that it travels 120 feet.

Explanation:

The range of a projectile is the horizontal distance covered by a projectile, which can be written as;

r = (u^2× sin2θ)/g

Where;

r = range

u = initial speed

θ = angle from horizontal

g = acceleration due to gravity

Solving for θ,

sin2θ = rg/u^2

θ = 1/2 × sin⁻¹(rg/u^2) 1

Given;

r = 120 ft

u = 115 ft/s

g = 9.81m/s = 32.2 ft/s

Substituting the values into the equation 1;

θ = 1/2 × sin⁻¹(120×32.2/115^2)

θ = 1/2 × sin⁻¹(0.29217)

θ = 1/2 × 17.00

θ = 8.50°

To the nearest angle

θ = 9.0°