A small rubber ball is launched by a compressed-air cannon from ground level with an initial speed of 17.3 m/s directly upward. Choose upward as the positive direction in your analysis. (a) What is the maximum height above the ground that the ball reaches?

h=15.27m

Explanation:

Since at maximum height the vertical velocity must be null it's better to use the formula:

We will use this formula for the vertical direction, choosing the upward direction as the positive one, so we have:

or

which for our values is:

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s