The kinetic energy of an object of mass m and velocity v is given by
Let's call
the initial speed of the car, so that its initial kinetic energy is
where m is the mass of the car.
The problem says that the car speeds up until its velocity is twice the original one, so
and by using the new velocity we can calculate the final kinetic energy of the car
so, if the velocity of the car is doubled, the new kinetic energy is 4 times the initial kinetic energy.
An important aspect of fission reactions is that they produce free neutrons, which causes chain reactions.
In order to draw the free body diagram, first let's calculate the friction force acting on the crate:
Since the friction force is greater than the force applied, the crate will not move, and the friction force will be equal to the force applied.
The weight force is equal to 40 * 9.8 = 392 N.
So, drawing the diagram, we have:
Thermal conductivity is the ability of a material to conduct heat.
hope this helped:)
(1) Doubling of the current through the wire will result in doubling of its magnetic field.
The magnetic field around a wire is a function of the current I and radial distance r
(with mu denoting the magnetic permeability of the medium). So, B is directly proportional to I. The field magnitude will double with the doubled current from 5A to 10A
(2) Using the same formula as in (1), we can see that the magnetic field is inversely proportional to the radial distance from the wire. So, a particle at 20cm will experience half the magnitude compared to a particle at 10cm.
(3) Answer
If a particle with a charge q moves through a magnetic field B with velocity v, it will be acted on by the magnetic force
So, a particle with charge -2uC will experience a magnetic force of same magnitude but opposite direction (and perpendicular to B) as compared to a particle with a charge of 2uC