Question

A ball was thrown from the ground at a speed of 20 m/s at 30 deg. Determine the horizontal and vertical displacements traveled by the ball at 1.25 s.

Answer 1

Gravitational acceleration = g = -9.81 m/s²

Initial velocity of the ball = V₀ = 20 m/s

Angle at which the ball is thrown = = 30^o

Initial horizontal velocity of the ball = V_x0 = V₀Cos = (20)Cos(30) = 17.32 m/s

Initial vertical velocity of the ball = V_y0 = V₀Sin = (20)Sin(30) = 10 m/s

Horizontal displacement of the ball after 1.25 sec = R

Vertical displacement of the ball after 1.25 sec = H

Time period = T = 1.25 sec

H = V_y0T + gT²/2

H = (10)(1.25) + (-9.81)(1.25)²/2

H = 4.84 m

There is no horizontal force on the ball therefore there is no horizontal acceleration.

R = V_x0T

R = (17.32)(1.25)

R = 21.65 m

a) Horizontal displacement of the ball after 1.25 sec = 21.65 m

b) Vertical displacement of the ball after 1.25 sec = 4.84 m