physics
posted by Anonymous .
How long does it take an automobile traveling in the left lane of a highway at 65.0 km/h to overtake (become even with) another car that is traveling in the right lane at 40.0 km/h when the cars' front bumpers are initially 80 m apart?

Divide the initial separation distance by the relative velocity.
80 m/(105,000 m/h) = 0.000762 h = 0.457 min = 2.74 seconds 
where did u get 105,000 m/h from?

He got the 105,000 by adding the Initial Velocities together.

Barry Bonds hits a home run so that the baseball just clears
the top row of bleachers, 21.0 m high, located 130 m from
home plate. The ball is hit at an angle of 35.0° to the horizontal,
and air resistance is negligible. Find (a) the initial
speed of the ball, (b) the time at which the ball reaches the
cheap seats, and (c) the velocity components and the speed
of the ball when it passes over the top row. Assume the ball
is hit at a height of 1.00 m above the ground.