v(t) = v(0) + ½ a t
Given:
g = -9.8m/s
t = 7.99s
Half way up the ball will reach 0 velocity.
0 = v + ¼ g t
Alternatively, all the way back, the ball will have a velocity equal but opposite to its initial.
-v = v + ½ g t
Use either equation to solve for v.
A ball is thrown vertically upward, which is the positive direction. A little later it returns to its point of release. The ball is in the air for a total time of 7.99 s. What is its initial velocity? Neglect air resistance.
4 answers
Correction:
use v(t) = v(0) + a t
v(½ t) = 0, so: 0 = v + ½ g t
v(t) = -v, so: -v = v + g t
use v(t) = v(0) + a t
v(½ t) = 0, so: 0 = v + ½ g t
v(t) = -v, so: -v = v + g t
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3 answers