# Homework Help: Mechanics question.

1. Oct 11, 2008

### Raed

1. The problem statement, all variables and given/known data

Two cyclists, A and B, have displacements 0 Km and 70 Km, respectively. At t = 0 they begin to cycle towards each other with velocities 15 Km/hr and 20 Km/hr, respectively. At the same time, a fly that was sitting on A starts flying towards B with a velocity of 30 Km/hr. As soon as the fly reaches B it immediately turns around and flies towards A, and so on until A and B meet.

a) What will the displacement of the two cyclists and the fly be when all three meet?

b) What will be the distance travelled by the fly?

2. Relevant equations

x = ut + 0.5at^2
v^2 = u^2 + 2as
v= at+u

3. The attempt at a solution

attempted a method of graphing but failed and attempted fill in variables in equations but failed again

2. Oct 11, 2008

### nasu

There is no acceleration in this problem. The two cyclists move with constant velocities.
Try to find out when will they meet. The equations of motions are just
d1=v1*t
d2=v2*t
with the distances measured from A and B respectively.
What is d1+d2 when they meet?