(a) A projectile is launched upward from ground level with aninitial speed of 98
ID: 3092361 • Letter: #
Question
(a) A projectile is launched upward from ground level with aninitial speed of 98 m/s. How high will it go? When will it returnto the ground? (b) Luis wanted to throw an apple to Kim, who was on a balcony40 ft above him, so he tossed it upward with an initial speed of 56ft/s. Kim missed it on the way up, but then caught it on the waydown. How long was the apple in the air? (a) A projectile is launched upward from ground level with aninitial speed of 98 m/s. How high will it go? When will it returnto the ground? (b) Luis wanted to throw an apple to Kim, who was on a balcony40 ft above him, so he tossed it upward with an initial speed of 56ft/s. Kim missed it on the way up, but then caught it on the waydown. How long was the apple in the air?Explanation / Answer
a) assuming y-axis is up, one of the distance equations is v^2=u^2-2gd at max height H, v= final speed = 0, u=98, 0=98^2-2(9.8)(H) H = 98^2/(2*9.8)= 490 m time t taken to reach max. height is given by v = u-gt 0=98-(9.8)t t= 10 s so it will return to ground in time 2t = 20 s b) here u=56 ft/s, g=32 ft/s^2, so max height H is given by 0=56^2-2(32)H H = 56^2/64 = 49 ft time taken to reach H is t = u/g = 56/32 = 1.75 s now for the downward trip from 49 ft to 40 ft, we can use d = ut + (1/2)gt^2 9 = 0 + (1/2)(32)t^2 t = 3/4 s = .75 s total time = 1.75+.75 = 2.5 s
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.