A particle of charge #-2*10^-9#C 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"#