Question

An object with a charge of -2.7 μC and a mass of 1.5×10^−2 kg experiences an upward electric force, due to a uniform electric field, equal in magnitude to its weight.

Required:
a. Find the magnitude of the electric field.
b. Find the direction of the electric field.
c. If the electric charge on the object is doubled while its mass remains the same, find the direction and magnitude of its acceleration.
d. If the electric charge on the object is doubled while its mass remains the same, find the direction and magnitude of its acceleration.

Answer 1

A. Using E = mg/q

= 1.5*10^-2 x 9.8/-2.7*10^-6C

=-5.4*10^4N/C

B. To find the direction of the electric field let's remember that the direction of field is always in opposite to that if applied force in this case force is upwards so field will be downwards

C. To find acceleration we use

a= Eq/m

So

= 5.4E4 x -2.7*10^-6/ 1.5*10^-2

= 9.72m/s²

D acceleration always follows direction of force so its upwards