A hoodlum throws a stone verticlly downwarsd with an inital speed of 12m/s from the roof of a building,30m above the ground

a)How long does it take the stone to reach the ground?

b)What is the speed of the stone at impact?

What would be the 2 equations for this problem?

a) Solve
Y = 30 - 12 t - (1/2) g t^2 = 0 for the elapsed time, t.
g = 9.8 m/s^2.
Take the positive root of the quadratic equation you get.
b) V (at impact) = Vinitial + g t
= -12 - 9.8 t
It will be a negative number (downwards)

  1. 👍 0
  2. 👎 0
  3. 👁 218
  1. 1.54 seconds
    27.092 m/s

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics/calculus

    A stone is thrown straight up from the edge of a roof, 600 feet above the ground, at a speed of 12 feet per second. A. Remembering that the acceleration due to gravity is -32 feet per second squared, how high is the stone 6

  2. physics

    a student standing on the roof of a 50 meter high building kicks a stone at a horizontal speed of 4 meters per second, how much time is required for the stone to reach the level ground below?

  3. physics

    While standing at the edge of the roof of a building, you throw a stone upward with an initial speed of 6.93 m/s. The stone subsequently falls to the ground, which is 17.1 m below the point where the stone leaves your hand. At

  4. physics

    Joshua throws a stone horizontally from a cliff at a speed of 20m/s, which strikes the ground 2.0 seconds later a. use your knowledge of vectors and show that the stone strikes the ground at a speed of about 28m/s. b. At what

  1. physic

    A stone is dropped from the roof of a high building. A second stone is dropped 1.00s laterHow far apart are the stones when the second one has reached a speed of 12.0m/s ?

  2. 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:

  3. physics

    A student stands at the edge of a cliff and throws a stone horizontally over the edge with a speed of 12.6 m/s. The cliff is 49.1 m above a flat horizontal beach as shown in the figure. a.How long after being released does the

  4. Physics

    A ball is thrown horizontally from the roof of a building 9.0 m tall and lands 8.5 m from the base. What was the ball's intial speed? I have no idea how to do this problemm or what formulas to use because of the fact that I do not

  1. physics

    . An inquisitive physics student and mountain climber climbs a 50.0-m cliff that overhangs a calm pool of water. He throws two stones vertically downward, 1.00 s apart, and observes that they cause a single splash. The first stone

  2. physics

    A stone is dropped from the roof of a tall building. A person measures the speed of the stone to be 49 m/s when it hits the ground. What is the height of the building?

  3. Physics

    a stone is thrown at an angle of 30 degrees above the horizontal from the top edge of a cliff with an initial speed of 12m/s. a stop watch measures the stone's trajectory time from top of cliff to bottom to be 8s. how far out from

  4. science (physics)

    how far will a stone travel over level ground if it is thrown upward at an angle 30 with the horizontal and with a speed of 12m/s?what maximum range could be achieved with the same initial speed?

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