Question

A projectile starting from ground hits a target on the ground located at a distance of 100 meters after 4 seconds.

a) What is the size of the angle θ?
b) At what initial velocity was the projectile launched?

Answer 1

In projectile motion, the path of the projectile is a parabola. The angle at which the projectile is launched is 0 degrees and the initial velocity of the projectile is 100 m/s.

Step-by-step explanation:

In projectile motion, the path of the projectile is a parabola. In this case, the projectile starts and ends at ground level, so the initial and final heights are the same. Since the projectile takes 4 seconds to hit the target, the time of flight is 4 seconds.

a) To find the angle θ, we can use the equation tan θ = (2v0y) / g, where v0y is the initial vertical velocity and g is the acceleration due to gravity. Since the projectile lands at the same height from which it was launched, the vertical displacement is zero, so v0y = 0. Plugging in the values, we find that θ = 0°.

b) To find the initial velocity, we can use the equation range = (v02 * sin(2θ)) / g, where the range is the horizontal distance traveled. Plugging in the values, we find that the initial velocity v0 = 100 m/s.