At a certain location close to earth's surface, we observe a uniform electric field of magnitude 105 n/c directed straight down. what must be the charge (in c) that needs to be placed on a person of mass 81 kg in order to make them lose contact with the ground? make sure to correctly identify the sign of the charge needed.

- 7.56 C

Explanation:

E = 105 N/C downwards

m = 81 kg

Let the charge on the man is q.

To lose te contact with the ground, the electrostatic foece should be balanced by the weight of the person.

The charge should be negative in nature so that the direction of electrostatic force is upwards and weight is downwards.

q E = m g

q = (81 x 9.8) / 105 = 7.56 C