Answer:
Explanation:
We have the following relation between power, P and intensity, I

= 
= 
We also have the following relationship between electric field and electromagnetic radiation thus

Hence 
substituting the values of I, c and e, we have

Answer:
ball clears the net
Explanation:
= initial speed of launch of the ball = 20 ms^{-1}
= angle of launch = 5 deg
Consider the motion of the ball along the horizontal direction
= initial velocity = 
= time of travel
= horizontal displacement of the ball to reach the net = 7 m
Since there is no acceleration along the horizontal direction, we have
Eq-1
Consider the motion of the ball along the vertical direction
= initial velocity = 
= time of travel
= Initial position of the ball at the time of launch = 2 m
= Final position of the ball at time "t"
= acceleration in down direction = - 9.8 ms⁻²
Along the vertical direction , position at any time is given as

Since Y > 1 m
hence the ball clears the net
Electrical generator which operates using a magnetic field. It is the beginning of modern dynamos.
Answer:
any person who opens the door he applies pulling force
Answer:

Explanation:
Frictional force due to road is pushing the cycle in forward direction
so it is given as f1
also the air drag is always in opposite direction of motion so it is given as f2
so here net force on the bicycle is given as

now initially the speed of cycle is increasing with time
so here we can say that net force on the cycle must be positive in direction
so we have

so we have
