According to newton's second law of motion, how much force will be required to accelerate an object at the same rate if its mass is reduced by half? a. no change in the amount of force is needed. b. four times the amount of force is needed. c. twice the amount of force will be required. d. half the amount of force will be required.

Any color picture tube and electric field exerts a net force of magnitude 1.68x 10^-13 n on an electron the rest mass of an electron is 9.11 x 10^-13 what is the electron acceleration?

All the simple machines make work easier to do by changing the or of a force. a. size; type b. work; type c. size; direction d. type; direction

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.