physics

1)A hiker throws a ball at an angle of 21.0 above the horizontal from a hill 21.0 m high. The hiker's height is 1.750 m. The magnitudes of the horizontal and vertical components are 14.004 m/s and 5.376 m/s, respectivley. Find the distance between the base of the hill and the point where the ball hits the ground. (Consider the hiker's height while calculating the answer.)

just te1l me what direction to go in please.

2)A car of mass 1330 kg is traveling at 28.0 m/s. The driver applies the brakes to bring the car to rest over a distance of 79.0 m. Calculate the retarding force acting on the car.

(79.0/28.0)*1330
3752.5

  1. 👍 0
  2. 👎 0
  3. 👁 164
  1. Assume the ball starts its upward flight from the top of the throwers head, 1.75m above the ground.

    1--Time to maximum height above the thrower's head derives from Vf = Vo - 9.8t or 0 = 5.376 - 9.8t making t(up) = .548sec.
    2--Time back to the top of the throwers head is also .548sec. and the velocity the same as the departure velocity, 5.376m/s.
    3--The time to reach the ground from the height of 21 + 1.75 = 22.75m = Vot + 9.8t^2/2 or 4.9t^2 + 5.376t - 22.75 = 0.
    4--Solve for t using the quadratic formula.
    5--Having t, the horizontal distance traveled becomes 14.004(.548 + .548 + t)

    1. 👍 0
    2. 👎 0
  2. 15.3

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics

    A hiker throws a ball at an angle of 21.0 degrees above the horizontal from a hill 21.0 m high. The hiker's height is 1.750 m. The magnitudes of the horizontal and vertical components of the velocity are 14.004 m/s and 5.376 m/s,

    asked by Willie on September 21, 2009
  2. precalculus

    Berry is standing at the edge of a hill that slopes downward and to the right. He notices that for every 5 feet you go in a horizontal direction, the hill drops by 2 feet. Berry places a ball at the edge of the hill (the origin of

    asked by Anonymous on June 10, 2013
  3. science

    girl throws the ball with a certain angle. It covers maximum horizontal distance R. How much height ball reaches if she throws the same ball vertically upward? Assume her muscles give the ball same speed in each case.

    asked by amol on August 14, 2012
  4. physics

    A boy throws a ball at 5.5 m/s at an angle of 25.4° above the horizontal off a cliff which is 70.8 m high. What angle does the velocity of the ball make with the horizontal 0.78 s after the throw? (make the angle positive if the

    asked by vince on December 6, 2012
  5. Physics

    An 80 kg hiker climbs a 1000 m high hill at a constant speed. If the hiker's body is 25% efficient, how many kg of fat does the hiker burn in climbing the hill? Given: heat of reaction of body fat is 37000 kilo joules per

    asked by Bobby on February 15, 2014
  6. precalculus

    Berry is standing at the edge of a hill that slopes downward and to the right. He notices that for every 5 feet you go in a horizontal direction, the hill drops by 2 feet. Berry places a ball at the edge of the hill (the origin of

    asked by Anonymous on June 10, 2013
  7. physics

    A child throws a ball with an initial speed of 8 m/s at an angle of 40 degrees above the horizontal. The ball leaves her hand 1 m above the ground. How long is the ball in flight before it hits the ground? What is the magnitude of

    asked by Melissa on September 19, 2010
  8. Physics

    Lily throws a ball at an angle of 53.13 degrees above the horizontal from a building that is 10m high. The ball has a speed of 12m/s, .6 seconds after she throws it. What was the initial speed of the ball? This is a vector problem

    asked by Hasan on November 6, 2015
  9. Physics

    If a box is being pulled up a hill at an angle to find work, its W=Fdcos(angle) If a hiker is walking up a hill, the work done is W=mgh right? When do you know when you can use what formula?

    asked by John on March 14, 2011
  10. Physics

    A man throws a ball horizontally from the top of a hill 4.9m high. He wants the ball to clear a fence 2.4m high, standing on a horizontal surface and 8m horizontally away from the point of projection. Find the minimum speed at

    asked by Kiran on February 13, 2014

More Similar Questions