Amachine launches a tennis ball at an angle of 25° above the horizontal at a speed of 14 meters per second. the ball returns to level ground. which combination of changes must produce an increase in time of flight of a second launch?
a. decrease the launch angle and decrease the ball’s initial speedb. decrease the launch angle and increase the ball’s initial speedc. increase the launch angle and decrease the ball’s initial speedd. increase the launch angle and increase the ball’s initial speed

D. increase the launch angle and increase the ball’s initial speed

Explanation:

for a body undergoing a projectile motion ,the time of flight will be the following

t=(2usin∅)/g

t=time of flight

u= the velocity a body undergoes during the motion

g=gravitational constant(9.81m/s^2)

∅=launch angle

mathematically, as the velocity and angle of inclination increases the time of flight also increases provided that g is constant .

D. increase the launch angle and increase the ball’s initial speed

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.