The electric field 14.0 cm from the surface of a copper ball of radius 2.0 cm is directed toward the ball's center and has magnitude 9.0 ✕ 10^2 n/c. how much charge is on the surface of the ball (in c)? (include the sign of the value in your answer.)

Q = - 256 X 10⁻⁷ C .

Explanation:

Electric field due to a charge Q at a distance d from the center is given by the expression

E = k Q /d² Where k is a constant and it is equal to 9 x 10⁹

Put the given value in the equation

9 x 10² =

Q =

Q = - 256 X 10⁻⁷ C .

It will be negative in nature as the field is directed towards the center.

e

explanation:

there is no change in the electric potential energy as it is in rest on both conditions.

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