An alpha particle travels at a velocity of magnitude 550 m/s through a uniform magnetic field of magnitude 0.045T. (An alpha particle has a charge of charge of +3.2 x 10-19 C and a mass 6.6 x 10-27 kg) The angle between the particle's direction of motion and the magnetic field is 52°. What happens to the speed? The answer is that the speed remains the same and I want to know why and how would we know if the speed changes ( there are two questions before this about the force and acceleration force is 6.2x10^-18 and acceleration is 9.5x10^8 )

the force is perpendicular to the speed, it is a type of force that changes the direction of the speed, as in the uniform circular motion te, but does not change its modulus.

Explanation:

The magnetic force is given by the expression

    F = q v x B

The bold are vectors, where v is the velocity and B is the magnetic field, the product is the cross product whose result is a vector perpendicular to the two vectors (v and B)

From the above, the force is perpendicular to the speed, it is a type of force that changes the direction of the speed, as in the uniform circular motion te, but does not change its modulus.

Even when the change in direction is real and is caused by a centripetal force

For there to be a change in the velocity modulus there must be a force parallel to the velocity direction, generally a force in electrical

thermal energy is the answer

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.