Hysical science is defined as the study of observable phenomena in the universe.
<span>the main idea of physical science is known as the "scientific method". </span>
<span>this method states: </span>
<span>observe a "real" ( not imaginary ) phenomena. </span>
<span>make a hypothesis ( or theory / idea ) that EXPLAINS this phenomena. </span>
<span>conduct a real experiment to test this hyothesis. </span>
<span>confirm that the experiment validates the original hypothesis and if necessary amend the theory. </span>
<span>it has worked so well that the very communication you are having with me is a result of the wonders of physical science. </span>
Let say the two train cars are of masses 
and 
now if the speed of two cars are 
and 
then we can say that the momentum of two cars before they collide is given by
here two cars are moving in opposite direction so we can say that the net momentum is subtraction of two cars momentum.
Now since in these two car motion there is no external force on them while they collide
So the momentum of two cars are always conserved.
hence we can say that the final momentum of two cars will be same after collision as it is before collision
Answer:
u=speed, w=wavelenght, f=frequency
It's known that u=w*f => f=u/w
u=20m/s ==> f=20/0,5 => f=40 Hz
w=0,50m
Explanation:
Angle α between the velocity of theelectron and the magnetic field of the wire will be 90 degree
Net Force = (mass) x (acceleration) (Newton #2)
Net Force = (50 kg) x (6 m/s² down)
Net Force = (50 * 6) (kg-m/s² down)
<em>Net Force = 300 Newtons down</em>
