A cannonball is shot from the top of a 30 𝑚 high hill at a velocity of 25 𝑚/𝑠 and at an angle of 40° above the horizontal and lands on the ground below. what is the speed

Question

motion in 2 dimensions

A. 0

B. 16 𝑚/𝑠

C. 19 𝑚/𝑠

D. 25 𝑚/𝑠

E. 29 𝑚/𝑠

Answer 1

Use the equation y= -30 + 25sin40°t -4.9t² which gives 4.9t² -16.07t -30 =0 solve for t using the quadratic formula and this gives t= 4.61s and hence v_y =16.07 - 9.8•4.61 = -29.11m/s which is E.