you throw a ball from a cliff with an initial velocity of 15m/s at an angle of 20° below the horizontal.find(a) its horizontal displacement and(b) its vertical displacement 2.3sec later?

Answer 1

Resolve the initial velocities into the
horizontal component, vx =v0 cos(θ)
and the
vertical component, vy= v0 sin(θ)
where θ=-20 degrees (below horiz.)

The horizontal component is subjected to only air resistance which in general is neglected, so travels at a uniform velocity.

The vertical component is subjected to the acceleration due to gravity, so use the formula
Δx=x0+v0(t)+(1/2)gt^2
x0=initial displacement = 0
v0=initial vertical velocity as given above.
g=acceleration due to gravity = -9.81 m/s^2