Answer:
632.8 nm is the wavelength (in air) of red light from a helium neon laser.
It's and if, then statement!
Acceleration....................................... <span />
v = speed of car = 90 km/h
u = speed of truck = 50 km/h
d = initial separation distance = 100 m = 0.1 km
They meet at time t such that
vt = d + ut
t(v - u) = d
t = d/(v - u) = (0.1 km) / [(90 - 50) km/h] = 0.0025 hours