[Projectile Motion Numerical]

How can the height be -ve!? :/

It doesn't make sense...

[Helping / Seeking Help vs. Cheating]

:eagerness:

[Projectile Motion Numerical]

Data:

V₀x= 30m/s

H₁= 2.4 m

V₀y= 0

X= 12m

H₂= 0.9m

To find:

(a) Will the ball clear the net?

( X’= ?

Solution:

(a) X= V₀x t

12=30 t

12/30 = t

t= 0.4 s

As, H=V₀y t + ½ g t²

H= (0)(0.4)+1/2(-9.8)(0.4)²

H= -0.78m

-ve sign shows that the height of the ball at the net from the top.

Height of the ball at the net and from the ground= H₁-H=2.4-0.78=1.62m

As 1.62m>0.9m so the ball will clear the net.

( H₁= V₀y t’ + ½ g t’²

-2.4= (0)t’ + ½ (-9.8) t’²

.

.

.

t’= 0.69s

X’=V₀x t’

X’=(30)(0.96)

X’= 20.7m

This is the solution my teacher came up with and honestly I have no idea whats going on? :/

[Projectile Motion Numerical]

Q:A tennis ball is served horizontally from 2.4m above the ground at 30m/s

(a)The net is 12m away and 0.9m high, will the ball clear the net?

(b)Where will the ball land?

:sorrow: