physics

posted by .

a ball rolls down a roof that makes an angle of 30 to horizontal.it rolls off the egde with a speed of 5.00m/s.distance to the ground from that point is 7.00m
a)how long is the ball in the air
b)how far from the base of the house does it land?
c)what is its speed just before landing?

  • physics -

    v(ox) = v•cosα =5•cos30 = 4.33 m/s,
    v(x) = v(ox) = 4.33 m/s,
    v(oy) = v•sinα =5•sin30 = 2.5m/s.
    h =v(oy) •t+g•t^2/2,
    4.9•t^2 +2.5•t-7 =0
    t = 1.05 s.
    L =v(ox) •t = 4.33•1.05 = 4.55 m
    v(y) = v(oy) + g•t = 2.5 +9.8•1.05 = 12.8 m/s,
    v=sqrt{v(x)^2 + v(y)^2} = 13.5 m/s.

  • physics -

    quadratic equation is solved incorrectly 4.9•t^2 +2.5•t-7 =0
    t IS NOT = 1.05 s , it is 0,967047 seconds.
    then put this time to solve other stuff

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Math/Physics

    A ball rolls horizontally off the edge of a tabletop that is 1.60 m high. It strikes the floor at a point 1.58 m horizontally away from the table edge. (Neglect air resistance.)How long was the ball in the air?
  2. Physics

    A ball of radius 0.300 m rolls along a horizontal table top with a constant linear speed of 3.30 m/s. The ball rolls off the edge and falls a vertical distance of 2.50 m before hitting the floor. What is the angular displacement of …
  3. physics

    A ball of radius 0.2m rolls along a horizontal table top with a constant linear speed of 3.04 m/s. The ball rolls off the edge and falls a vertical distance of 2.02m before hitting the floor. What is the angular displacement of the …
  4. physics

    A golf ball rolls off a horizontal cliff with an initial speed of 14.1 m/s. The ball falls a vertical distance of 14.0 m into a lake below. (a) How much time does the ball spend in the air?
  5. physics

    A ball rolls with a speed of 6.4 m/s toward the edge of a table that is 0.7 m above the floor. The ball rolls off the table. a. Find the magnitude of the balls velocity when it hits the floor. m/s b. At what angle, measured from the …
  6. physics

    A ball of radius 0.211 m rolls along a horizontal table top with a constant linear speed of 3.41 m/s. The ball rolls off the edge and falls a vertical distance of 2.27 m before hitting the floor. What is the angular displacement of …
  7. Physics

    A golf ball rolls off a horizontal cliff with an initial speed of 12.2 m/s. The ball falls a vertical distance of 17.3 m into a lake below. (a) How much time does the ball spend in the air?
  8. Physics

    A ball rolls down a 1.00 m long and 0.40 m inclined plane and falls off down on the floor, 1.20 m. a) Calculate the speed of the ball when it falls of the plane and the speed in vertical and horizontal direction. b) Where does the …
  9. Physics

    A target lies flat on the ground 4 m from the side of a building that is 10 m tall, as shown below. The acceleration of gravity is 10 m/s2 . Air resistance is negligible. A student rolls a 4 kg ball off the horizontal roof of the building …
  10. Physics

    The roof of a two-story house makes an angle of 29° with the horizontal. A ball rolling down the roof rolls off the edge at a speed of 4.5 m/s. The distance to the ground from that point is 8.2 m. (a) How long is the ball in the air?

More Similar Questions