An object with mass m is at rest on the floor. What is the magnitude and direction of the normal force acting on it? 1.N = mv in upward direction
2.N = mg in upward direction
3.N = mv in downward direction
4.N = mg in downward direction

The human body stores chemical energy from digested food. some of the chemical energy is converted into mechanical energy when the body moves. which statement best supported by this information

Atotal charge of –6.50 µc is uniformly distributed within a sphere that has a radius of 0.150 m. what is the magnitude and direction of the electric field at 0.300 m from the surface of the sphere? a) 2.89 × 105 n/c, radially inward b) 6.49 × 105 n/c, radially outward c) 4.69 × 105 n/c, radially inward d) 9.38 × 105 n/c, radially outward e) 1.30 × 106 n/c, radially inward

Critical mass is the of material required to produce a chain reaction. a.) minimum amount b.) atomic mass c.) precise amount d.) maximum amount