bouncing ball projectile motion question

I need help finding the velocity, V2, of a ball after it strikes a frictionless flat horizontal surface. I'm given that V1 (the launch velocity) = 10 m/s, and the ball is launched at an angle pi/4.

I'm told that the vertical velocity of the ball at the instant of the bounce changes by a factor of 0.2, and there isn't any change in horizontal velocity.

so far I've resolved the initial velocity to it's horizontal and vertical components using equations:
V1y = V1*sin(pi/4)
V1x = V1*cos(pi/4)

however I don't know the next steps are to finding the velocity after it bounces.
pls help (I've included a paint drawing of the problem)

bouncingballquestion.jpg16.2KB

Reply 1

kkboyk

21

Original post by dila247

I need help finding the velocity, V2, of a ball after it strikes a frictionless flat horizontal surface. I'm given that V1 (the launch velocity) = 10 m/s, and the ball is launched at an angle pi/4.

I'm told that the vertical velocity of the ball at the instant of the bounce changes by a factor of 0.2, and there isn't any change in horizontal velocity.

so far I've resolved the initial velocity to it's horizontal and vertical components using equations:
V1y = V1*sin(pi/4)
V1x = V1*cos(pi/4)

however I don't know the next steps are to finding the velocity after it bounces.
pls help (I've included a paint drawing of the problem)

Consider the vertical motion from v1: find the heigth of the ball from v1 to its maximum height (where v=0). After finding the height, you can find V2 using the value of the height found, its initial speed (which will be 0 from its maximum height), acceleration will be 9.8m/s.

Do the same method to find the final velocity (V3) after it hits the ground a second time.

Reply 2

username1560589

20

Original post by dila247

I need help finding the velocity, V2, of a ball after it strikes a frictionless flat horizontal surface. I'm given that V1 (the launch velocity) = 10 m/s, and the ball is launched at an angle pi/4.

I'm told that the vertical velocity of the ball at the instant of the bounce changes by a factor of 0.2, and there isn't any change in horizontal velocity.

so far I've resolved the initial velocity to it's horizontal and vertical components using equations:
V1y = V1*sin(pi/4)
V1x = V1*cos(pi/4)

however I don't know the next steps are to finding the velocity after it bounces.
pls help (I've included a paint drawing of the problem)