The magnitude of the resultant force is given by the centripetal force, since the car is under a circular motion. So, we have:

The centripetal acceleration is given by:

Where v is the linear speed and r the radius of the circular motion. Replacing this and solving:

Answer:
Explanation:
A proton and electron are moving in the positive x direction, this shows that their velocity will be in the positive x direction
V = v•i
Magnetic field Is the positive z direction
B = B•k
A. For proton.
Proton has a positive charge of q
Direction of force on proton
Force is given as
F = q(v×B)
F = q( v•i × B•k)
F = qvB (i×k)
From vectors i×k = -j
F = -qvB •j
Then, for the positive charge, the force will act in the negative direction of the y-axis
B. For electron
Electron has a negative of -q
Direction of force on proton
Force is given as
F = q(v×B)
F = -q( v•i × B•k)
F = -qvB (i×k)
From vectors i×k = -j
F = --qvB •j
F = qvB •j
Then, for the negative charge, the force will act in the positive direction of the y-axis
Here, Initial momentum = mu = 6*2 = 12 Kg m/s
Final momentum = mv = 6*4 = 24 Kg m/s
In short, Your Answer would be Option C
Hope this helps!
Vi=0m/s
Vf=?
A=9.81
D=44
T=not needed
Vf^2=Vi^2+2ad
Vf=2ad square rooted
Vf=2(9.81)(44) square root it
Vf=29.3m/s