Question

A particle of mass 2 kg and charge 1 mC is projected vertically with a velocity $10m{s}^{-1}$. There is a uniform horizontal electric field of ${10}^4$ N/C. Then,

• A. the time of flight of the particle is 4s.
• B. the time of flight of the particle is 2s.
• C. the maximum height reached is 5 m.
• D. the maximum height reached is 10m.

Answer 1

Answer: (B), (C)

The correct options are
B the time of flight of the particle is 2s.
C the maximum height reached is 5 m.

Time of flight $\left(T\right)=\frac{2u}{g}=\frac{2\times 10}{10}=2S;H=\frac{u^2}{2g}=5m$
Horizontal Range $\left(R\right)=a\times T$
Where $a$ is acceleration, and $a=qE/m=5$
Therefore$R=5\times 2=10$