Answer:
C 1. A. An object is in motion if its position changes relative to another object. B. Velocity must have a measurement of speed and direction below.
A 2. A. Distance and displacement are equal.
B. Distance is less than displacement.
B 3. A. When a car goes around a corner at 20 mph, the car is accelerating because it's changing direction.
B. A value that only has magnitude is called scalar.
B 4. A. Speed is a vector quantity.
B. A car is speeding up while traveling forward when its velocity is positive and its acceleration is also positive.
Explanation:
1. A reference point is a place or object used for comparison to determine if something is in motion. An object is in motion if it changes position relative to a reference point.
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement.
2. Distance is always greater than or equal to displacement. First let's define the terms : Distance:It is the actual path length travelled by an object within a specified time interval. Displacement:Displacement is the shortest length between starting and stopping point of that object.
3. When a car goes around a corner at a constant speed of 20 mph, why do we say it accelerates? The car is accelerating because of the velocity is constant. The car accelerates because the speed is constant at 20 mph.
A quantity which does not depend on direction is called a scalar quantity. Vector quantities have two characteristics, a magnitude and a direction. Scalar quantities have only a magnitude.
4. Speed is a scalar quantity because it does not need a direction of motion, it only needs magnitude. We can add speeds without considering the direction of motion.
When an object is speeding up, the acceleration is in the same direction as the velocity. Thus, this object has a positive acceleration.
