Answer:
No the given statement is not necessarily true.
Explanation:
We know that the kinetic energy of a particle of mass 'm' moving with velocity 'v' is given by

Similarly the momentum is given by 
For 2 particles with masses
and moving with velocities
respectively the respective kinetic energies is given by


Similarly For 2 particles with masses
and moving with velocities
respectively the respective momenta are given by


Now since it is given that the two kinetic energies are equal thus we have

Thus we infer that the moumenta are not equal since the ratio on right of 'i' is not 1 , and can be 1 only if the velocities of the 2 particles are equal which becomes a special case and not a general case.
Answer:
<em>The comoving distance and the proper distance scale</em>
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Explanation:
The comoving distance scale removes the effects of the expansion of the universe, which leaves us with a distance that does not change in time due to the expansion of space (since space is constantly expanding). The comoving distance and proper distance are defined to be equal at the present time; therefore, the ratio of proper distance to comoving distance now is 1. The scale factor is sometimes not equal to 1. The distance between masses in the universe may change due to other, local factors like the motion of a galaxy within a cluster. Finally, we note that the expansion of the Universe results in the proper distance changing, but the comoving distance is unchanged by an expanding universe.
Answer:
Time, t = 0.015 seconds.
Explanation:
Given the following data;
Mass, m = 0.2kg
Force, F = 200N
Initial velocity, u = 40m/s
Final velocity, v = 25m/s
To find the time;
Ft = m(v - u)
Time, t = m(v - u)/f
Substituting into the equation, we have;
Time, t = 0.2(25 - 40)/200
Time, t = 0.2(-15)/200
Time, t = 3/200
Time, t = 0.015 seconds.
Note: We ignored the negative sign because time can't be negative.