Physics
posted by Anonymous .
A stone is thrown up vertically from the ground (the gravitational acceleration is g = 10 m/s^2 ). After a time dt =1 s, a second stone is thrown up vertically. The first stone has an initial speed v1 = 11.0 m/s, and the second stone v2 = 16.0 m/s.
(a) At what time after the first stone is thrown will the two stones be at the same altitude above ground? (in seconds)

a. h1 = V1*t + 0.5g*t^2
h1 = 11*1  5*1^2 = 6 m. Head start.
V^2 = V1^2 + 2g*h
V^2 = 11^2  20*6 = 1
V = 1.0 m/s.
h2=V2*t + 0.5g*t^2 = 6 + V*t + 0.5g*t^2
16*t  5*t^2 = 6 + 1*t  0.5g*t^2
The 0.5g*t^2 terms cancel:
16t  t = 6
15t = 6.0
t = 0.4 s. to catch up.
Respond to this Question
Similar Questions

physics
Two stones are thrown vertically up at the same time. The first stone is thrown with an initial velocity of 11.5 m/s from a 12thfloor balcony of a building and hits the ground after 4.0 s. With what initial velocity should the second … 
physics
Two stones are thrown vertically up at the same time. The first stone is thrown with an initial velocity of 12.5 m/s from a 12thfloor balcony of a building and hits the ground after 4.6 s. With what initial velocity should the second … 
physics
A stone with mass m = 2.3 kg is thrown vertically upward into the air with an initial kinetic energy of 190 J. The drag force acting on the stone throughout its flight is constant, independent of the velocity of the stone, and has … 
Physics
Help imediately please very urgent! A stone is dropped from a cliff 200m high,if a second stone is thrown vertically upwards 1.50sec after the first was released,strike the base of the cliff at the same in stant as the first stone,with … 
Physics
A stone is dropped from rest from the roof of a 100m high building; 2.00 s after that, a second stone is thrown straight down with initial speed v0, and the second stone passes the first stone 21.6 m above ground. (a) When are the … 
physics
Two stones are thrown vertically up at the same time. The first stone is thrown with an initial velocity of 11.5 m/s from a 12th floor balcony of a building and hits hits the ground after 4.6 seconds. With what initial velocity should … 
physics
A stone is dropped into a river from a bridge 45.4 m above the water. Another stone is thrown vertically down 1.14 s after the first is dropped. Both stones strike the water at the same time. What is the initial speed of the second … 
physics
A stone is dropped into a river from a bridge 45.4 m above the water. Another stone is thrown vertically down 1.14 s after the first is dropped. Both stones strike the water at the same time. What is the initial speed of the second … 
physics
A stone is dropped into a river from a bridge 43.8 m above the water. Another stone is thrown vertically down 1.65 s after the first is dropped. Both stones strike the water at the same time. What is the initial speed of the second … 
PSU
A 2.3kg stone is thrown from ground directly upward. the maximum height reached by the stone is 45m. Neglecting air resistance, a) with which initial speed was the stone thrown?