A charged particle of mass `m= 2kg` and charge `1 muC` is thrown from a horizontal ground at an angle of `45^(@)` with horizontal with a spedd of `10m//s`. In space a horizontal electric field `E= 2xx10^(7)N//C` exists. Find the range of the projectile

Options

A. `5 m`
B. `30 m`
C. `10 m`
D. `20m`

Answer

D

Explanation

`a_(x)= (qE)/(m)= (10^(-6)xx2xx10^(7))/(2)= 10 m//s^(2)`

Time of flight `T= (2u sin theta)/(g)= (2xx10xx1/sqrt(2))/(10)= sqrt(2)s`
Hence, Range `R= u_(x)T+1/2a_(x)T^(2)`
`R= 10 cos 45^(@) xxT+1/2a_(x)T^(2)`
`=(10)/(sqrt(2))xxsqrt(2)+1/2xx10xx2= 20m`