Physics
posted by JC .
A rock is thrown vertically upward with a speed of 11.0 from the roof of a building that is 70.0 above the ground. Assume free fall.
In how many seconds after being thrown does the rock strike the ground?
What is the speed of the rock just before it strikes the ground?
The smart aleck answer is, "If it's thrown straigt up then how can it land on the ground? It should land on the roof, right?"
Ignoring that, figure out how long it will rise and what it's velocity will be when it returns to the building's height, then use that for the initial velocity if it had been thrown off the building.
Once again I see that you're not supplying units so I don't know what to make of the question.

Physics 
save
refer to the other qs
Respond to this Question
Similar Questions

Physics
A rock is thrown vertically upward with a speed of 11.0 m/s from the roof of a building that is 70.0 m above the ground. Assume free fall. In how many seconds after being thrown does the rock strike the ground? 
Physics
A rock is thrown vertically upward with a speed of 12.0 from the roof of a building that is 40.0 above the ground. Assume free fall. In how many seconds after being thrown does the rock strike the ground? 
physics
A rock is thrown vertically upward with a speed of 14.0 m/s from the roof of a building that is 50.0 m above the ground. Assume free fall. In how many seconds after being thrown does the rock strike the ground? 
Physics
A small rock is thrown vertically upward with a speed of 17.0m/s from the edge of the roof of a 32.0m tall building. The rock doesn't hit the building on its way back down and lands in the street below. Air resistance can be neglected. … 
PHYSICS
A rock is thrown vertically upward with a speed of 14.0m/s from the roof of a building that is 70.0m above the ground. Assume free fall. In how many seconds after being thrown does the rock strike the ground? 
Physics
A rock is thrown directly upward from the edge of a flat roof of a building that is 56.3 meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Take the acceleration … 
Physics
A small rock is thrown vertically upward with a speed of 14.0m/s from the edge of the roof of a 25.0m tall building. The rock doesn't hit the building on its way back down and lands in the street below. Air resistance can be neglected. … 
Physics
A rock is thrown directly upward from the edge of the roof of a building that is 35.3 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 effects … 
Physics
A small rock is thrown vertically upward with a speed of 17.0m/s from the edge of the roof of a 22.0m tall building. The rock doesn't hit the building on its way back down and lands in the street below. Air resistance can be neglected. … 
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 effects …