Answer:
The statement "The magnetic field of a magnet comes out of the north pole and goes into the south pole" is imprecise
Explanation:
This is because the zero divergence equation (∇ · B = 0 ) is valid for any magnetic field, even if it is time dependent rather than static. Physically, it means that there are no magnetic charges otherwise we would have ∇ · B ∝ ρmag instead of ∇ · B = 0. Consequently, the magnetic field lines never begin or end anywhere in space; instead they form closed loops or run from infinity to infinity.
Answer:
When the starting and ending points are the same, the total work is zero.
Explanation:
option ( D )correct
A force is said to be conservative when the work done by the force in moving a particle from a point A to a point B is independent of the path followed between A and B and is the same for all the paths. The work done depends only on the particles initial and final positions. And when the initial and final position in conservative field are same the work done is said to be zero.
Sound travels fastest in solids,than liquids, and faster in liquids, than in gases.
Answer:
The acceleration of the crate is 
.
Explanation:
Given that,
Force, F = 750 N
Mass of the crate, m = 250 kg
The coefficient of friction is 0.12.
We need to find the acceleration of the crate. The net force acting on the crate is given by :
f is frictional force, 
So, the acceleration of the crate is . Hence, this is the required solution.
