Answer:
Explanation:
We shall apply concept of impulse
Impulse = Force x time
= Force x 2 x 10⁻³ N.s
impulse = change in momentum
change in momentum
= .4 x 4 - ( - .4 x 2 )
= 2.4
Force x 2 x 10⁻³ = 2.4
Force = 2.4 / 2 x 10⁻³
= 1.2 x 10³ N .
average magnitude of the force exerted by floor = 1.2 x 10³ N
If R be reaction force by earth
R - mg = 1.2 x 10³
R = 1.2 x 10³ + mg
= 1200 + .4 x 9.8
= 1200 +3.92
= 1203 .92 N .
Answer:
(a) 
(b) 
Explanation:
It is given that,
Force acting on the particle, F = 12 N
Displacement of the particle, 
Magnitude of displacement, 
(a) If the change in the kinetic energy of the particle is +30 J. The work done by the particle is given by :
is the angle between force and the displacement
According to work energy theorem, the charge in kinetic energy of the particle is equal to the work done.
So,
(b) If the change in the kinetic energy of the particle is (-30) J. The work done by the particle is given by :
Hence, this is the required solution.
Answer:
The nuclei are moving fast with respect to one another
Explanation:
Protons are found in the nucleus together with the neutrons while the electrons normally revolve round it.
However the protons appears fused in a way when electromagnetic force is applied by the nuclei moving at a very fast speed. This fast speed helps to keep the supposed neutrons fused together.
The event in the life of a star that begins its expansion into a giant is its core that was hot enough for fusion reaction.
<h3>What is fusion reaction?</h3>
Nuclear fusion is a type of reaction in which two or more atomic nuclei are fuse to form one or more different atomic nuclei with the release or the absorption of energy.
So we can conclude that the event in the life of a star that begins its expansion into a giant is its core that was hot enough for fusion reaction.
Learn more about reaction here: brainly.com/question/26018275
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Answer:
A
Explanation:
All of the other answers don't make much sense
