Four particles enter a region of uniform magnetic field with velocities perpendicular to magnetic field lines. The particles have the following masses and charges: 1 : charge q; velocity v and mass m
2: charge 29 velocity 2v and mass 2m
3: charge q: velocity 3v, mass m/2
4: charge 2q: velocity 30, mass 2m
Rank the radii of theirs paths for these particles, largest to smallest

r4 > r2 > r3 > r1

Explanation:

correction of the statement:

The particles have the following masses and charges:

1 : charge q; velocity v and mass m

2: charge 2q velocity 2v and mass 2m

3: charge q: velocity 3v, mass m/2

4: charge 2q: velocity 3v, mass 2m

In order to calculate the radius of the trajectories of the four particles, you use the following formula for the radius of the trajectory of a particle in a perpendicular and constant magnetic field:

                (1)

m: mass of the particle

v: speed of the particle

q: charge

B: magnitude of the magnetic field

Then, in comparison with the equation (1), you obtain for each case:

1 : charge q; velocity v and mass m

= r

2: charge 2q velocity 2v and mass 2m

3: charge q: velocity 3v, mass m/2

4: charge 2q: velocity 3v, mass 2m

By the previous results you can conclude:

r4 > r2 > r3 > r1

gravity

explanation:

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.