2. Before 0.5-kg ball is dropped from a third story window 20 m above the sidewalk. What is the potential energy of the ball?
a. 4 J
b. 9800 J
C. 98 J
d. 150 J

Explain vector addition, triangle method and parallelogram method

When considering gravity acceleration and the force of acceleration, what must be true? a. the direction of acceleration must be perpendicular to the direction of the force. b. the direction of the force and the direction of acceleration must be the same as each other. c. the direction of the force and the direction of acceleration must be opposite of each other. d. the mass of the body must be the same as the acceleration of the body.

Why can blue light and yellow light combine to produce white light? question 17 options: they are both primary colors of light. they absorb each other's wavelengths. because blue, yellow, and white are primary colors. they are complementary colors of light.