Physics

posted by .

4. A football player passes the ball. The ball leaves his hand and is caught 1.7 seconds later by a receiver 30 meters away. (You may assume the ball was caught at the same height from which it was thrown.)
a) What is the vertical component of the velocity of the ball just after it is released?
b) What is the speed (the magnitude of the velocity) of the ball when it is at the top of its trajectory?
c) What is the speed (the magnitude of the velocity) of the ball just before it is caught?

  • Physics -

    vx(t) = vx0
    vy(t) = vy0 - g*t
    y = vy0*t - 1/2*g*t^2
    x = vx0*t

    where y is vertical distance measured from the height of the football player's hand, x is the horizontal distance, t is time, vy0 is the initial speed in the y direction, vx0 is the initial speed in the x direction, and vy(t) is the speed in the y direction as a function of time, and vx(t) is the speed in the x direction as a function of time

    When the football player catches the ball at 1.7s, the vertical height y is back at 0, and the horizontal distance is at 30

    0 = vy0*1.7 - 1/2*g*1.7^2
    30 = vx0*1.7

    Solve for vy0 and vx0

    a) The vertical component of the velocity of the ball just after it is released is vy(t) evaluated at t = 0
    vy(t) = vy0
    b) At the top of its trajectory, the ball will be exactly halfway to the receiver, so t = 1.7/2 = 0.85 s. At this time
    vy(t) = vy0 - g*0.85
    vx(t) = vx0

    solve
    then the magnitude of the speed is

    (vy(t)^2 + vx(t)^2)^0.5

    c) Just before the ball is caught, t = 1.7s

    vy(t) = vy0 - g*1.7
    vx(t) = vx0

    solve for vy(t) and vx(t), and then use the formula from part b to calculate the magnitude of the vector

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Physics

    The ball spins at 7.7 rev/s. In addition, the ball is through with a linear speed of 19 m/s at an angle of 55 degrees with respect to the ground. If the ball is caught at the same height at which it left the quarterback's hand, how …
  2. physics

    A quarterback is asked to throw a football to a receiver that is 32.1 m away. What is the minimum speed that the football must have when it leaves the quarterback's hand?
  3. physics

    PLEASE I HAVE NO IDEA WHERE TO START A quarterback is asked to throw a football to a receiver that is 32.1 m away. What is the minimum speed that the football must have when it leaves the quarterback's hand?
  4. Dynamics

    A quarterback throws a football with a velocity vo at an angle of 45o with the horizontal. At the same instant a receiver standing 20 ft in front starts running down the field at 15 ft/s and catches the ball. What is the distance of …
  5. Physics

    A quarterback is asked to throw a football to a receiver that is 32.6 m away. What is the minimum speed that the football must have when it leaves the quarterback's hand?
  6. Physics

    A quarterback throws a pass at an angle of 40 degrees above the horizontal with an initial speed of 20 m/s. The ball is caught by the receiver 2.55 seconds later. Determine horizontal velocity, vertical initial velocity, the distance …
  7. Physics

    A quarterback throws a pass at an angle of 40 degrees above the horizontal with an initial speed of 20 m/s. The ball is caught by the receiver 2.55 seconds later. Determine horizontal velocity, vertical initial velocity, the distance …
  8. Physics

    A player throws a ball at an initial velocity of 36 m/s. The maximum distance the ball can reach (assume ball is caught at the same height at which it was released) is?
  9. Physics

    a softball batter hits a fly ball that is caught 3.8 seconds later, 88m from home plate. The ball is caught at the same height from which it was thrown. What was its initial velocity?
  10. Physics

    A quarterback throws a spiral to a receiver that is 40m away. The football has a spin of 14 rev/s and went through 58 revolutions before being caught. if the ball is caught at the same height it was thrown at, at what velocity and …

More Similar Questions