Simple physics quesiton i just cant get?

Question

A ball is thrown upward with initial speed w.
a)what is the max height?
b)time to max height?

Answer 1

Time to the maximum height is the easier to do. It is just the initial velocity divided by the acceleration due to gravity.

For example, if an object is thrown upward at 30 meters/second from the surface of the earth, it will travel upward for 30/9.81 seconds, or a little more than 3 seconds.

Once you know the time, it is easy to compute the distance.

d = 1/2 * g * t^2

where g is the acceleration due to gravity.

Answer 2

General formula for distance,

s = wt - 1/2 g t^2

Differentiate to get velocity,

ds/dt = w - gt

Equate to zero to find maximum point

w - gt = 0

t = w/g

Substitute t = w/g to find the max height

s = wt - 1/2 g t^2

s = w(w/g) - 1/2 (g) (w/g)^2

s = w^2/g - 1/2 w^2/g

s = 1/2 w^2/g

a) Max height is (1/2 w^2/g)

b) Time to Max height is (w/g)

Answer 3

what kind of ball are you talking about? A soft ball , football, basketball, bowling ball, golf ball? I am no physics major or rocket scientist but I would think that the type of ball would make a big difference as to the max height no matter what the initial speed upward was.

Answer 4

Depends on the gravity, the air pressure, the ball frontal surface, the (air) resistant factor (ball material).

Here are the formulaes if throwing many variables out:
http://en.wikipedia.org/wiki/Acceleration_due_to_gravity

Answer 5

a)v^2=u^2-2as
v=0, u= w, g=acceleration of free fall
(w^2)/2g = max height

b)g = change in velocity/ time
change in vel = dv = vfinal -vinitial =w-(-w) = 2w
g=acceleration of free fall
time = g/2w

Answer 6

Velocity at it's maximum height is zero.

Answer 7

v(0) = w
a(t) = - g

where g is the gravitation acceleration (9.81 m/s^2)


v(t) = d/dt a(t) = (-g) * t + v(0)

x(t) = d/dt v(t) = (-g/2) * t^2 + v(0) * t + x(0)

let x(0) = 0

a) at max height, x_max, v(t) = 0

b) 0 = (-g) * t + w
t = w/g

x_max = x(w/g) = (-g/2) * (w/g)^2 + w * (w/g)
x_max = w^2 * (1/g - 1/2g)
x_max = (w^2) / 2g

Answer 8

simple, what is g equal to on your planet? Does it have any atmospheric resistance?