I don't think that 4m has anything to do with the problem.
anyway. here.
A___________________B_______C
where A is the point that the train was released.
B is where the wheel started to stick
C is where it stopped
From A to B, v=2.5m/s, it takes 2s to go A to B so t=2
AB= v*t = 2.5 * 2 = 5m
The train comes to a stop 7.7 m from the point at which it was released so AC=7.7m
then BC= AC-AB = 7.7-5 = 2.7m
now consider BC
v^2=u^2+2as
where u is initial speed, in this case is 2.5m/s
v is final speed, train stop at C so final speed=0, so v=0
a is acceleration
s is displacement, which is BC=2.7m
substitute all the number into equation, we have
0^2 = 2.5^2 + 2*a*2.7
0 = 6.25 + 5.4a
a = -6.25/5.4 = -1.157
so acceleration is -1.157m/(s^2)
<span>g = GMe/Re^2, where Re = Radius of earth (6360km), G = 6.67x10^-11 Nm^2/kg^2, and Me = Mass of earth. On the earth's surface, g = 9.81 m/s^2, so the radius of your orbit is:
R = Re * sqrt (9.81 m/s^2 / 9.00 m/s^2) = 6640km
here, the speed of the satellite is:
v = sqrt(R*9.00m/s^2) = 7730 m/s
the time it would take the satellite to complete one full rotation is:
T = 2*pi*R/v = 5397 s * 1h/3600s = 1.50 h
Hope it help i know it's long and may be confusing but if you have any more questions regarding this topic just hmu! :)</span>
Answer:
when a two bodies A and B are moving at an angle 180° with each other then the relative velocity is the sum of bodies the velocity .i.e,
when the bodies move the opposite direction
then their relative velocity is the sum of individual velocities.