Question

what force must be exerted on an electron to move it from a state of rest to a speed of 3.5 x 10^7 m/s in a distance of 0.75 m?


Look up the mass of the electron and call it m. Then compute the required acceleration a, using
V = sqrt(2 a X)
(Solve that for a)

For the force required, use

F = m a

Answer 1

what force must be exerted on an electron to move it from a state of rest to a speed of 3.5 x 10^7 m/s in a distance of 0.75 m?

V^2=Vo^2+2ax

3.5x10^7=2a(0.75)

3.5x10^7=1.50a

divide by 1.50 on both sides to get "a" by itself

a = 2.3x10^7 m/s^2

next use Newton's 2nd law F=ma

F=(9.1x10^-31)(2.3x10^7) *9.1x10^-31 is the mass of the electron)

your answer is F = -1.3x10^3 Newtons

Done.

Answer 2

you need to Square 3.5x 10^7 so that its (3.5x 10^7)^2 / 1.50 = a