1212.54 is what 550 kgs is equal to the weight of the car
This one is simple :)
use the equation F = ma and then re-arrange for a.
a = F / m
But there is a trick, so be careful. the question gives you wind resistance. Simply subtract the wind resistance from the thrust of the rocket to get the net force upward.

So,
So what we can do is apply the<span> Hooke's law wich states that
F = -kx ( P.S the -ve sign means opposite in direction )
Also we will need to determine the spring's constant with the formula:
k = F / x
Where F = the force ( = 20 N )
x = the displacement of the end of the spring from it's position ( = 0.20 m )
k = the spring's constant ( = unknown )
So this would be: k = 20 / 0.20 = 100 N/m
The period of oscillation of 4 kg : T = 2 * pi * square root m / k
T = 2 * pi * square root 4 / 100
T = 1.256 seconds
Hope it helps</span>
<span>1. They’re invisible - RADIO WAVES
2. They have colors. - VISIBLE LIGHT WAVES
3. They’re used to learn about dust and gas clouds. - BOTH
4. They can travel in a vacuum. </span> - BOTH<span>
5. They’re used to find the temperature of stars. </span>- VISIBLE LIGHT WAVES<span>
6. They have energy. </span> - BOTH