Answer:
Repulsion is the sure test for magnetism because it occurs only when two like poles of a magnet exist while the attraction phenomenon can occur between two unlike poles of a magnet and also between a magnet and a magnetic material means if there are two magnets they will attract each other and suppose if one material
Answer:
The total time is 
.
Explanation:
Given:
The distance between Galactic Capitol and Earth is, 
The speed of light is, 
The time taken by the message to reach and come back to Earth is given by
In addition they take 1 year to decide to reply.
Thus, the total time is 
.
<span>the transverse wve that requires a medium to move is : sound waves
in order to travel, sound waves need to jumped on between one particle to another, no matter it's liquid, solid , and gases. Which explains why you wont hear a thing in outer space, simply because the sound waves got no particle to jumped into</span>
Answer:
The change in momentum of the car is 30,000 kg m/s
Explanation:
Given,
The force exerted on the car to slow down, F = 7500 N
The time period of force, t = 4 s
The rate of change of momentum of the object is equal to the force acting on it.
Therefore,
<em> (mv - mu) / t = F</em>
Where v and u are the final and initial velocity of the car. The change in momentum of the car,
mv - mu = F x t
= 7500 x 4
= 30,000 kg m/s
Hence the change in momentum of the car is 30,000 kg m/s
