Answer:
F = W + ma a> 0
Explanation:
For this exercise let's use Newton's second law
we assume the upward direction as positive
F - W = m a
F = W + ma
F = m (g + a)
In this case they indicate that the speed is less and less as it goes down, therefore the acceleration must be opposite to the speed, that is, the acceleration is upwards, consequently it is positive
We can see that since a> 0 the force F must have greater than the weight of the elevator
Answer:
Current in the toroid will be 
Explanation:
We have given number of winding in rectangular toroid N = 1500
Self inductance of toroid L = 0.06 H
Magnetic energy stored in toroid 
We have to find the current in the toroid
Magnetic energy stored is equal to 


So current in the toroid will be 
Answer:
0.25
Explanation:
Friction force is the normal force times the coefficient of friction.
F = Nμ
50 N = (200 N) μ
μ = 0.25
earth still is not solid ... core is molten ... volcanoes, sea is liquid
at v v v beginning was gas ????