# physics

While standing at the edge of the roof of a building, you throw a stone upward with an initial speed of 7.65 m/s. The stone subsequently falls to the ground, which is 11.1 m below the point where the stone leaves your hand. At what speed does the stone impact the ground? How much time is the stone in the air? Ignore air resistance and take g = 9.81 m/s2.

1. 👍 0
2. 👎 0
3. 👁 2,547
1. v = 7.65 - 9.81 t

h = 11.1 + Vi t - 4.9 t^2
0 = 11.1 + 7.65 t - 4.9 t^2
solve quadratic for t, time at h = 0, ground, use the positive answer :)
then do
v = 7.65 - 9.81 t for the speed

1. 👍 0
2. 👎 1
2. 12.06 for speed
2.01 for time

1. 👍 0
2. 👎 0

## Similar Questions

1. ### 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

asked by unknwon on October 10, 2014
2. ### Physics

You are walking around your neighborhood and you see a child on top of a roof of a building kick a soccer ball. The soccer ball is kicked at 41° from the edge of the building with an initial velocity of 21 m/s and lands 59 meters

asked by Jennifer on October 10, 2013
3. ### 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

asked by kloe on February 7, 2017
4. ### physics

While standing on a bridge 15.0 m above the ground, you drop a stone from rest. When the stone has fallen 3.10 m, you throw a second stone straight down. What initial velocity must you give the second stone if they are both to

asked by brittany on January 31, 2010
5. ### 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

asked by Megan on April 8, 2016
1. ### Calculus

A stone is dropped from the edge of a roof, and hits the ground with a velocity of -195 feet per second. How high is the roof? .

asked by Anonymous on November 14, 2011
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?

asked by jack on January 16, 2011
3. ### physics

A brick mason is on a steep roof repairing a chimney and drops a brick. If the brick slides down the roof and leaves the edge of the roof with the velocity v = (1.00 m/s)î − [(6.00 m/s) + (9.80 m/s2)t]ĵ, determine the

asked by Anonymous on August 30, 2018
4. ### Geometry

Christopher wants to determine how far away a helicopter is from where he is standing. He knows the helicopter is sitting on the edge of a roof of an apartment building that is 400 feet high and 1,050 feet from where he is

asked by Morgan on March 16, 2014
5. ### physics

a rock is directly thrown upward from the edge of a roof of a building that is 56.3m tall. the rock misses the building on its way down, and is observed to strike the ground 4 seconds after being thrown. with what speed was the

asked by elias on March 23, 2018