Question

multiple choice questions answer the following multiple choice questions about the reading. 1. what is the primary role of static friction? a. to reduce the weight of heavy objects. b. to prevent movement between two surfaces in contact. c. to increase the speed of moving objects. d. to oppose the motion of two surfaces sliding against each other. 2. according to the passage, in what scenario is kinetic friction at work? a. a car parked on a hill. b. a hockey puck sliding across the ice. c. tires rolling without slipping. d. a box that doesnt move when pushed. 3. why is it generally easier to keep an object moving than to start moving it? a. static friction increases as an object moves faster. b. static friction is usually less than kinetic friction. c. kinetic friction increases as an object moves faster. d. kinetic friction is usually less than static friction.

Explanation:

1. Static friction acts to prevent relative motion between two surfaces in contact that are at rest relative to each other.
2. Kinetic friction occurs when two surfaces are in relative motion. A hockey - puck sliding across the ice has two surfaces (puck and ice) in relative motion.
3. Static friction is the force that must be overcome to start an object moving, and it is generally greater than kinetic friction which acts once the object is already in motion.

Answer:

1. B. To prevent movement between two surfaces in contact.
2. B. A hockey puck sliding across the ice.
3. D. Kinetic friction is usually less than static friction.