Answer:
A force is a push or pull that acts upon an object as a result of that objects interactions
Explanation:
Average speed =
(total distance)/(total time)
Average speed = (99+90)/(2+3)
That's (189 km) / (5 hr)
Average speed = 37.8 km/hr
1. Frequency: 
The frequency of a light wave is given by:

where
is the speed of light
is the wavelength of the wave
In this problem, we have light with wavelength

Substituting into the equation, we find the frequency:

2. Period: 
The period of a wave is equal to the reciprocal of the frequency:

The frequency of this light wave is
(found in the previous exercise), so the period is:

Acceleration is how much the velocity changes within a period of time so,
Acceleration= is the change in velocity divided by change in time
your units will be m/s squared