Two copper spheres are placed 0.04 m apart on a horizontal surface. The charge of sphere A is -4 microCoulombs, while sphere B has a charge of +2.0 microCoulombs. Which of the following statements is correct? (1 microCoulomb = 1 x 10-6 Coulombs) Group of answer choices:

1. Sphere A will feel a smaller electric force compared to sphere B.

2. The magnitude of the force exerted on sphere B will be 45 N and the force will be attractive.

3. The magnitude of the force exerted on sphere A will be double the force exerted on sphere B.

4. Both spheres will feel an attractive force towards each other. The magnitude of the force will be 4.5 x 10^13 N.

Arock collection comes from which part of earth?

For general projectile motion, when the projectile is at the highest point of its trajectory, its acceleration is zero? a)the horizontal and vertical components of its velocity are zero. b) its velocity is perpendicular to the acceleration. c)the horizontal component of its velocity is zero. d)its velocity and acceleration are both zero.

1point) a skydiver weighing 130 lb (including equipment) falls vertically downward from an altitude of 14,000 ft and opens the parachute after 20 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.85|v|0.85|v| when the parachute is closed and is of magnitude 17|v|17|v| when the parachute is open, where the velocity vv is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. find the speed of the skydiver when the parachute opens. speed is 150.6121788 ft/s find the skydiver's height when the parachute opens. height is 2338.98591 ft find the limiting velocity vlvl after the parachute opens. (think about whether this should be positive or negative.) vl=vl= 7.647 ft/s