Elements of electromagnetics
Answers
$F =q*(E+v times B)$ where $F$, $E$, $v$ and $B$ are vectors and $times$ is the vector product.
$F =q*[4*i + (10*j) times (5k)] = 4*i +50*i =54*i$ N
$F=m*a$
$a =54*i m/s^2$
$v =a*t +u0= 54*i+10*j$ m/s after $t =1 sec$
$s =at^2/2 +s0= 54*i/2+0 =27*i$ m
$E_k =m v^2/2 =1/2*(54*54+10*10) =1508 J$
7.
$F = q*E = 4i N$
$a =F/m = 4i$ m/s
$v = at+u0 =4i+10j m/s after t=1 sec$
$s = at^2/2=4*i/2*1^2 =2*i$ m
$E_k = m v^2/2 =1/2*(4*4+10*10) =58 J$
8.
$F=q(v times B) = 0$ because $u0=0$
$a =0 m/s^2$
$v =u0+at =0 m/s$
$s =0 m$
$E_k =0$