Posted by **Heidi** on Friday, November 12, 2010 at 1:31pm.

Beatrice throws the 1st calculator straight up from the edge of the roof of a building. She drops a 2nd calculator off the side of the building 2 seconds after she has thrown the first one. If the height of the building is 40m, what must the initial upwards velocity of the 1st calculator be so the two calculators to hit the ground at exactly the same time?

- Physics -
**bobpursley**, Friday, November 12, 2010 at 1:45pm
first calc: hf=hi+vi*t-4.9t^2

second calc: hf=hi-4.9(t-2)^2

0=40+vi*t-4.9t^2

0=40-4.9(t-2)^2 well, two equations, two unknowns. start the with the second, solve for time, then put that into the first equation and solve for vi.

## Answer this Question

## Related Questions

- Physics - A rock is thrown directly upward from the edge of the roof of a ...
- Physics - Jo student undertakes a unique experiment with his calculator. He goes...
- Physics Gr.11 - Frank stands at the base of a building. He throws a 0.12kg rock ...
- physics - Frank stands at the base of a building. He throws a 0.12kg rock ...
- Physics - A hammer is thrown horizontally from the flat roof of a tall building ...
- Physics - A rock is thrown vertically upward with a speed of 11.0 from the roof ...
- Physics - A ball is thrown at an angle of 37.1degrees above the horizontal from ...
- physics - bill and bob are both on the roof of a building 176.4 m high. bill ...
- physics - bill and bob are both on the roof of a building 176.4 m high. bill ...
- Physics - A rock is thrown directly upward from the edge of a flat roof of a ...

More Related Questions