A charge of 4.5 × 10-9 C is located 3.2 m from a charge of -2.8 × 10-9 C. Find the electrostatic force exerted by one charge on the other.

F = 1.1074 × N

Explanation:

An electrostatic force is either a force or attraction or repulsion between two charges. It can be determined by:

F =

where: F is the force, k is a constant, is the first charge, is the second charge and r the distance between the charges.

Given that: k = 9 × N, = 4.5 × C, = -2.8 × C and r = 3.2 m.

Then,

F =

 =

 = 1.1074 ×

The electrostatic force exerted is 1.1074 × N, and it is a force of attraction.

i think the answer is a, hope this : )

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s