Atennis player hits a ball 2.0 m above the ground. the ball leaves his racquet with a speed of 20 m/s at an angle 5.0 ∘ above the horizontal. the horizontal distance to the net is 7.0 m, and the net is 1.0 m high. does the ball clear the net?

ball clears the net

Explanation:

= initial speed of launch of the ball = 20 ms^{-1}

= angle of launch = 5 deg

Consider the motion of the ball along the horizontal direction

= initial velocity =

= time of travel

= horizontal displacement of the ball to reach the net = 7 m

Since there is no acceleration along the horizontal direction, we have

      Eq-1

Consider the motion of the ball along the vertical direction

= initial velocity =

= time of travel

= Initial position of the ball at the time of launch = 2 m

= Final position of the ball at time "t"

= acceleration in down direction = - 9.8 ms⁻²

Along the vertical direction , position at any time is given as

Since Y > 1 m

hence the ball clears the net

3. dark matter

empty space could also be a simple vacuum