There are two general types of collisions, inelastic and elastic.
Inelastic collisions occur when two objects collide but neither of them bounce away from each other.
Collisions in which the objects do not touch each other are elastic. (Ex: Rutherford Scattering)
Answer:
2,4,5
Air pressure is created by the weight of the atmosphere pushing on Earth’s surface.
Denser air is heavier than less dense air.
Air is less dense at higher altitudes.
The formula for velocity vf = vi + at
First list your given information
2m/s Is your initial velocity (vi)
6m/s is you final velocity (vf)
2 seconds is your time (t)
Since you want the a for acceleration get a by itself
a = (vf-vi)/t
So a= (6-2)/2
a= 4/2
a=2
Now units
the units for acceleration are m/s

2m/s
Answer:
five characteristics: Wavelength, Amplitude, Time-Period, Frequency and Velocity or Speed