A ball is thrown straight up iwht an initial speek of 30m/s. How high does it go? How long is it in the air?

Answer 1

use
v^2=u^2+2as
v=0 since it stops at last in the air before coming back
a=-g=-9.8m/s^2
0=30^2+2(-9.8)s
900=19.6s
s=900/19.6
=45.9 meters Ans.

v=u+at
v=0
a=-9.8 m/s^2
0=30-9.8t
t=30/9.8
=3.01 sec. Ans.

Answer 2

with constant acceleration (or decelleration), which is "g", speed over time is:
v = gt - 30 (where 30 is initial speed)

this speed will become 0 when
0 = 9.81 t - 30, i.e. t = 30 / 9.81 = 3.06 sec

Now the distance travelled in that time would be
d = integral of (gt-30)
d = g/2 t^2 - 30t + c
given d=0 for t=0, c must be 0, therefore simplified
d = g/2 t^2 - 30t

Now for t=3.06 we get
d = 45.93 - 91.8 = -45.87 meters

Answer 3

Given: Vi = 30 m/s Vf = zero g = 9.8 m/(s^2) y initial = zero Want to find: the high = y final = ? time in air = 2*delta t = ? Note: ^2 means squared equations: 1) Vf^2 = Vi^2 - 2*g*(y final - y initial) 2) Vf = Vi - g*delta t (note: there is more than one equation to solve part B) solution: Part 1 use equation 1 to find y final Vf^2 = Vi^2 - 2*g*(y final - y initial) zero = 30^2 - 2*9.8*(y final - zero) 2*9.8*(y final - zero) = 30^2 y final = 30^2 / (2*9.8) = 45.9 m Part 2 use equation 2 to find delta t Vf = Vi - g*delta t zero = 30 - 9.8*delta t 9.8*delta t = 30 delta t = 30 / 9.8 = 3.06 s (this is upward) time in air = 2*delta t time in air = 2*3.06 = 6.12 s Note: delta t is the time for one way and since you want to find the time in air you multiply delta t by 2 (one way upward and one way downward and both of them are equal because you throw it by your hand and finally you catch it by your hand ). Some times y initial and y final differ ( as throwing a ball upward in air - y initial is your hand - and when it goes downward it passes your hand and goes in a ditch for example or hits the ground ) and in this case you should calculate delta t for upward and delta t for downward separately.

Answer 4

v = u - g.t
0 = 30 - 10.t
t = 3 seconds
h = ut - (1/2).g.t²
h = 90 - (1/2) x10 x 9
h = 45 m

Answer 5

111 m
114sec

Answer 6

what u know about math i know all about math the answer is 67