20 Physics -- Kinematics

A ball is projected at 5i + 20j from a tower of height 5m Find the following: The time of flightThe maximum heightThe maximum horizontal range

A ball is projected at 5i + 20j from a tower of height 5m Find the following:

The time of flight

The maximum height

The maximum horizontal range

1 Answers

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Given: u = 20,
s = -5 t = ?,
a = -10
We know,
s = ut + 1/2 at²
-5= 20t - 1/2 x 10 x t²
-5 = 20t - 5t²
5t² - 20t - 5 = 0
t = 4.2s or t = -0.2s
Time of flight = 4.2s
Given: u = 20,
a = -10,
v = 0,
s = ?
We have,
v² = u² + 2as
0 = 400 - 20s
s = 20m
Maximum height = 5 + 20 = 25m
Given: u = 5,
a = 0,
t = 4.2
s = 5 x 4.2sec
s = 21m

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