physics

A stone is thrown from the top of a building upward at an angle of 30.0∘to the horizontal and with an initial speed of 20.0 m/s. If the height of the building is 45.0 m, what is the speed in m/sec of the stone just before it strikes the ground ?

  1. 👍
  2. 👎
  3. 👁
  1. u = 20 cos 30 until it hits the ground.

    Vi = initial vertical velocity = +20 sin 30 = +10

    initial vertical displacement = 45
    final vertical displacement = 0

    0 = 45 + Vi t - 4.9 t^2
    solve for t

    v = Vi - 9.8 t
    solve for v

    speed = sqrt (u^2 + v^2)

    1. 👍
    2. 👎

Respond to this Question

First Name

Your Response

Similar Questions

  1. Math

    From the top of a 200 metres high building, the angle of depression to the bottom of a second building is 20°. From the same point, the angle of elevation to the top of the second building is 10°. Calculate the height of the

  2. PHYSICS

    A stone thrown from the top of a building is given an initial velocity of 40.0 m/s straight upward. The building is 70.0m high, and the stone just misses the edge of the roof on its way down, determine (A) The time at which the

  3. Physics

    A stone is projected upward at an angle of 30 degree to the horizontal from the top of a tower 100m and it hits the ground at a point q. If the initial veloity of projection is 100ms cal the maximum height of the stone above the

  4. physic

    A girl throws a stone from a bridge. Consider the following ways she might throw the stone. The speed of the stone as it leaves her hand is the same in each case. Case A: Thrown straight up. Case B: Thrown straight down. Case C:

  1. science

    Two stones are launched from the top of a tall building. One stone is thrown in a direction 30.0degree above the horizontal with a speed of 10.0m/s ; the other is thrown in a direction 30.0degree below the horizontal with the same

  2. Physics

    A rock is thrown directly upward from the edge of the roof of a building that is 40.2 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Neglect any

  3. Physics

    A stone thrown upward to just reach the top of a palm tree that is 8.2m tall. Calculate the initial speed that is require

  4. civil engineering

    A stone (on the edge of the roof) thrown from the top of a building is given an initial velocity of 20.0 m/s straight upward. The building is 50.0 m high, as shown in Fig. 4. Using tA = 0 as the time the stone leaves the

  1. Math

    A stone is thrown skyward from the top of building. The distance in feet between the stone and the ground in 't' seconds is given by the function h (t) = -16t(t) -4t+ 442. How long after the stone is thrown is it 430 feet from the

  2. Physics

    A brick is thrown upward from the top of a building at an angle of 25° to the horizontal and with an initial speed of 15m/s. If the brick is in the flightfor 3.0 s, how tall is the building?

  3. physics

    Stones are thrown horizontally, with the same initial velocity, from the tops of two different buildings, A and B. The stone from building A lands 4 times as far from the base of the building as does the stone from building B.

  4. Physics

    A stone is thrown vertically upward from the top of the tower with a velocity of 15m / s. Two seconds later a second stone is dropped from the top of the tower.if both the stone strike the ground simultaneously find the height of

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