Question

A ball is kicked at 30.0 m/s at an angle of 20.0°. Beneath the tilted columns calculate the vertical and horizontal components. Show all work in including starting equations. Vertical velocity Horizontal Velocity

Answer 1

The velocities at time t are

• Horizontal:

v = (30.0 m/s) cos(20.0º)

• Vertical:

v = (30.0 m/s) sin(20.0º) - g t

(where g = 9.80 m/s² is the magnitude of the acceleration due to gravity)

If you only want the initial velocities, they are

• Horizontal:

v = (30.0 m/s) cos(20.0º) ≈ 28.2 m/s

• Vertical:

v = (30.0 m/s) sin(20.0º) ≈ 10.3 m/s

(just set t = 0)

As far as starting equations go, you can derive everything from the definition for average acceleration:

a = ∆v / ∆t = (final v - initial v) / t

→   v = u + a t

(here, u stands in for "initial v" and v is simply velocity at time t )

There is no acceleration in the horizontal direction, while the ball is essentially in free-fall in the vertical direction.