Projectile launched at an angle

Question

During a fast break against Detroit, Derrick Rose rises up in the air for an alley-oop dunk. He jumps up at an angle of 41.5º above the horizontal at a velocity of 5.88 m/s. What is Derrick's vertical (y) velocity 0.31 seconds into his flight. Round your answer to 2 decimal places.

Answer 1

You need to break the 5.88 m/s velocity number into a vertical and horizontal component. Let y = the vertical component. Note that the sin(41.5°) = y/5.88. y = 5.88*sin(41.5°)= 5.88*.6626 = 3.89 m/s.

 

From this you need to subtract the effect of gravity which is applying a downward force of 9.8 m/s².

 

The formula to use is v=v₀ - gt

= 3.89 - 9.88*.31 = 3.89 - 3.06 = .83 m/s.