phy

A blue ball is thrown upward with an initial speed of 20.6 m/s, from a height of 0.8 meters above the ground. 2.5 seconds after the blue ball is thrown, a red ball is thrown down with an initial speed of 8.2 m/s from a height of 23.7 meters above the ground. The force of gravity due to the earth results in the balls each having a constant downward acceleration of 9.81 m/s2

1)What is the speed of the blue ball when it reaches its maximum height?
2)How long does it take the blue ball to reach its maximum height?
3)What is the maximum height the blue ball reaches?
4)What is the height of the red ball 3.25 seconds after the blue ball is thrown?
5)How long after the blue ball is thrown are the two balls in the air at the same height?

  1. 👍 0
  2. 👎 0
  3. 👁 4,962
  1. 1. Final velocity(Vf) = 0 @ max. ht.

    2. t = (Vf - Vo) / g,
    t = (0 - 20.6) / -9.8 = 2.1s.

    3. h = Vo*t + 0.5gt^2,
    h = 20.6*2.1 + 0.5*(-9.8)*(2.1)^2,
    h = 43.26 + (-21.6) = 21.65m above 0.8m.

    4. t = 3.25 - 2.5 = 0.75s.
    h = 23.7 - (V0*t + 0.5gt^2),
    h=23.7 - (8.2*0.75 + 0.5*9.8*(0.75)^2),
    h = 23.7 - (6.15 + 2.76),
    h = 23.7 - 8.91 = 14.79m Above ground.

    1. 👍 9
    2. 👎 5
  2. please answer the 5th part

    1. 👍 0
    2. 👎 2
  3. 5. h1 + h2 = 23.7m,
    (0.8+20.6t-4.9t^2)+(8.2t+4.9t^2)=23.7, 28.8t = 23.7 -0.8 = 22.9,
    t = 0.795s.

    Check:

    h1=0.8 + 20.6*0.795 -4.9*(0.795)^2 = 14.1m above ground(t = 0.795s).

    h2=23.7 - 8.2*0.795 + 4.9*(0.795^2 =
    23.7 -9.62=14.1m above groun(t=0.795s).

    1. 👍 0
    2. 👎 13
  4. I have noticed that the gravity for the blue ball is negative, while the red ball is positive? could you tell me why?

    1. 👍 0
    2. 👎 0
  5. regarding #5:
    That answer would be correct if both balls were thrown at the same time. The problem states the red ball was thrown downward 2.6 seconds after the blue ball was thrown. One solution is to determine the position and velocity of the blue ball at the time the red ball was thrown, and then use those as the initial condition.

    1. 👍 4
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. science

    a ball is thrown straight upward and returns to the thrower's hand after 3.00s in the air. A second ball is thrown at an angle of 30.0 deg with the horizontal. At what speed must the second ball be thrown so that it reached the

    asked by tani on September 8, 2009
  2. physics

    A ball is thrown upward at a speed v0 at an angle of 52.0˚ above the horizontal. It reaches a maximum height of 7.3 m. How high would this ball go if it were thrown straight upward at speed v0?

    asked by Shelby on February 18, 2012
  3. physics

    For a flourish at the end of her act, a juggler tosses a single ball high in the air. She catches the ball 3.6 s later at the same height from which it was thrown. Part A-What was the initial upward speed of the ball?2sf

    asked by ana22 on February 11, 2017
  4. physics science

    a ball thrown vertically upward lands on the thrower's hand 24.5s. find (a) the time taken by the ball to reach its maximum height,(b) the maximum height attained by the ball, and (c) initial velocity of the ball

    asked by john on September 8, 2017
  5. physics

    a ball is thrown at an initial angle of 37 and initail velocity of 23.0 m/s reaches a maximum height h, as shwon in the Figure. With what initial speed must a ball be thrown straight up to reach the same maximum height h?

    asked by Anonymous on January 3, 2011
  1. physics

    A ball of mass m = 0.75 kg is thrown straight upward with an initial speed of 8.9 m/s. Plot the gravitational potential energy of the block from its launch height, y = 0, to the height y = 5.0 m. Let U = 0 correspond to y = 0.

    asked by Bob on February 13, 2011
  2. physics

    A ball is thrown vertically upward with an initial speed of 20 m/s. Two seconds later, a stone is thrown vertically (from the same initial height as the ball) with an initial speed of 24 m/s. At what height above the release point

    asked by Derek on September 16, 2008
  3. Physics

    A red ball is thrown down with an initial speed of 1.3 m/s from a height of 28.0 meters above the ground. Then, 0.6 seconds after the red ball is thrown, a blue ball is thrown upward with an initial speed of 24.7 m/s, from a

    asked by Funnyguy on January 26, 2013
  4. Physics

    A ball is thrown straight upward and rises to a maximum height of 23 m above its launch point. At what height above its launch point has the speed of the ball decreased to one-half of its initial value?

    asked by Has on August 11, 2013
  5. Algebra

    A ball is thrown from an initial height of 2 meters with an initial upward velocity of 25m/s. The ball's height h (in meters) after t seconds is given by the following. Find all values of t for which the ball's height is 12

    asked by Anonymous on May 14, 2014

You can view more similar questions or ask a new question.