Distance run by the train at the moment t:
x = a * t^2 / 2
Distance run by the man, D
D = 9 m + distance run by the train
D = 9m + a(t^2) / 2
Velocity of the man, V = D/t => D = V*t
Equal D:
V*t = 9m + a(t^2) / 2
Now, you have to make an additional assumption. It is that when the man reaches the traing their velocities are the same. This if because, if the train is faster, the man will not reach it, and if the train is slower then he will pass the train (which is an unnecessary waste of effort from the man)
So, the best contition is that the speed of the train equals the speed of the man.
The speed of the train follows the equation of the uniformly accelerated motion: V = a.t
So from substitute that V in the equation V*t = 9m + a(t^2)/2
=> (at) t = 9m + a(t^2) / 2
=> a(t^2) - a(t^2) / 2 = 9m
=> a(t^2) / 2 = 9m
=> (t^2) = 9m * 2 / a = 9m * 2 / ( 2 m/s^2) = 9 s^2
=> t = 3 s
=> D = 9m + a(t^2) / 2 = 9 m + 2(m/s^2) (3s)^2 / 2 = 9m + 9 m = 18 m
=> V = D / t = 18 m / 3s = 6m/s
Answer:
The man ran 18 m.
He got into the train after 3 s
The full speed is 6 m/s
Answer:
Explanation:
We shall apply time dilution relation of relativity
t = 
t₀ = 1000 x .09987
= 99.87 days .
doubling time = 20 days
no of doubling time in 20 days ; n = 99.87 / 20
n = 4.9935
n = 
; n₀ is initial number , n is number finally .
= 2 x 2⁴°⁹⁹³⁵
= 64 approx .
I only know what number 1. is and its Mechanical Energy.
Answer:
344.8 Hz
Explanation:
The frequency of a wave is given by:
where
v is the speed of the wave
is its wavelength
Here we have
v = 793 m/s
Substituting into the equation, we find
Answer:
I believe this represents Newton's first law of motion. Any object in motion will continue to move until a force stops it, be it friction or a physical object.
