projectile motion (1 Viewer)

[fullonoob]

a ball is thrown with initial velo 20m/s at an angle of elevation arc tan (4/3)
Suppose that the ball is thrown up a road inclined at arc tan (1/5) to the horizontal. Show that:
The time of flight is 2.72 secs, and find the distance the has been thrown up the road.

Additional info you might need to know
x= 12t
y = 16t -5t^2
the ball is about 9m above the road when it reaches its greatest height.
Greatest height of the ball is 12.8m
Range = 38.4
Takes 8/5 secs to reach max height.

 

[Affinity]

a ball is thrown with initial velo 20m/s at an angle of elevation arc tan (4/3)
Suppose that the ball is thrown up a road inclined at arc tan (1/5) to the horizontal. Show that:
The time of flight is 2.72 secs, and find the distance the has been thrown up the road.

Additional info you might need to know
x= 12t
y = 16t -5t^2
the ball is about 9m above the road when it reaches its greatest height.
Greatest height of the ball is 12.8m
Range = 38.4
Takes 8/5 secs to reach max height.

x= 12t
y = 16t -5t^2

and you know that when it hits the surface,
5y = x (incline = arctan(1/5))

(16t -5t^2)*5 = 12t
25t^2 - 68t = 0
t(25t-68) = 0
t = 0 gives the initial point.. so at pont of impact, 25t - 68 = 0 t = 68/25 = 2.72
x = 32.64
y = 6.528
so the distance up the ramp is 33.28