A particle of charge -2*10^-9C is acted on by a downward electrostatic force of 3*10^-6 N when placed in this field. The gravitational and electrostatic force respectively exerted on a proton placed in this field are???

1 Answer
Sep 16, 2017

"Gravitational force": F = 1.64 cdot 10^(- 26) "N"

"Electrostatic force": F = 2.4 cdot 10^(- 16) "N"

Explanation:

Let's use the equation F = q E to find the magnitude of the electric field the particle is in:

Rightarrow F = q E

Rightarrow E = frac(F)(q)

Considering downwards to be the "negative" direction:

Rightarrow E = frac(- 3 cdot 10^(- 6) " N")(- 2 cdot 10^(- 9) " C")

therefore E = 1.5 cdot 10^(3) "N" cdot "C"^(- 1)

Then, we can apply the same equation to find the electrostatic force that will act on a proton if it were placed in this field:

Rightarrow F = 1.6 cdot 10^(- 19) "C" cdot 1.5 cdot 10^(3) "N" cdot "C"^(- 1)

therefore F = 2.4 cdot 10^(- 16) "N"

Now, the equation for the force due to gravity can be found using the equation F = m g:

Rightarrow F = 1.673 cdot 10^(- 27) "kg" cdot 9.81 "m" cdot "s"^(- 2)

therefore F = 1.64 cdot 10^(- 26) "N"