1. A ball is thrown downward with an initial speed of 20 m/s on Earth. a. What is the acceleration of the ball?

Assuming weightless pulleys and 100% efficiency, what is the minimum input force required to lift a 120 n weight using a single fixed pulley?

When a light bulb shines, it gives off light energy and energy. a. heat b. potential c. chemical d. electrical

Two forces produce equal torques on a door about the door hinge. the first force is applied at the midpoint of the door; the second force is applied at the doorknob. both forces are applied perpendicular to the door. which force has a greater magnitude?