Answer:
400 m
Explanation:
The swimmer swims 50 meters to one end of the pool but has to swim back therefore you double 50 which would be 100 meters. Then you have to multiply 100 by 4 since the swimmer did it 4 times.
The answer is B. On a sunny day, the air over a lake will be cooler than the air over the bordering land.
Answer:
that would be newtons 3rd law
Explanation:
because its how it is
Answer:
Explanation:
Electric field due to a point charge Q at a point at distance d is given by the relation
E = 
Since Q1 and Q2 are of the same magnitude and distance , so they will create eletric field of same magnitude. Similarly field due to rest of the charges will also be same.
The charges are situated on the corners of a square in such a way that
equal charges of Q1 and Q3 are situated on the diametrically opposite corners of the square. Fields due to these two charges will be equal and opposite in direction. Therefore net field due to these two charges will be zero.
On the same ground, we can say that field due to Q2 and Q4 at the centre will be equal and opposite and therefore they will cancel out each other. Net field at the centre will be zero
Overall, net field due to all the four charges will be zero