Question

physics please solve tomorrow is my exan

Answer 1

Velocity of the particle at time t,  v= u + at
                                                    v = 0 + (Eq/m)t

KE = (1/2)mv^2 = (B) option

Answer 2

Charge = q
Mass = m
Field = E
Time = t
Initial velocity u = 0 m/s

Let final velocity be v.
Let acceleration be 'a'.

(Note: Here, '×' means multiplication. It does not mean cross product here)

Now, Force F = q×E
So, m × a = q×E
So, a = (qE)/m

Now, motion of the charged particle is going to be uniformly accelerated.

So, v = u + at
So, v = 0 + (qE/m) t
So, v = qEt/m

Now, Kinetic Energy is
K = (1/2)×m×v^2

So, K = (1/2) m (qEt/m)^2
So, K = [(Eqt)^2]/2m

So, your answer is option B.

Good luck for your test.