Question

Sharon kicks a ball from the ground into the air with an upward velocity of 64 feet per second. Write a function that models the height h, in feet, of the ball at time t, in seconds. When will the ball reach the ground again?
A. 1 second after the ball is thrown
B. 2 seconds after the ball is thrown
C. 3 seconds after the ball is thrown
D. 4 seconds after the ball is thrown
Projectile motion:
h(t)= -16t^2+V_0t+h_0
Please help!! :(

Answer 1

-16t^2+64t+0?

Answer 2

hello :)

Answer 3

use the equation of motion for a projectile moving un der gravity

h = ut + (1/2)gt^2

where u = initial velocity, h = height, t = time and g = acceleration due to gravvity

here u = 64 fts-1 and g = -32 ft s-2

Answer 4

1D path, only force is gravity. initial conditions at h=0 and V = 64

Answer 5

h = 64t - 16t^2

Answer 6

the ball will reach the ground when h = 0
so you need to solve
64t - 16t^2 = 0

Answer 7

one solution will be t = 0 which corresponds to when the ball is first kicked

Answer 8

And the other is 4??

Answer 9

64t - 16t^2 = 0
16t(4 - t) = 0
4-t = 0
t = 4


Yes