Answer:
(a) Magnetic force

(b) Acceleration

(C) Speed will remain same
Step-by-step explanation:
We have given velocity of alpha particle v = 520 m/sec
Magnetic field B = 0.034 T
Charge on alpha particle

Mass of alpha particle

Angle between velocity and magnetic field 43°
(a) Force acting on the particle is equal to



(B) According to newton's law
F = ma. here m is mass and a is acceleration.
So acceleration

(c) As the magnetic force is always perpendicular to velocity so speed will remain same neither decreases nor increases.