Physics 80

joe can pitch a baseball a distance of 48 meters in 1.5 seconds. how fast is his pitch? a) 3.1 m/s b) 32 m/s c) 48 m/s d) 72 m/s

2) if c moves to position 5 (60 meters), what is its average velocity during these 5 seconds? a) 10 m/s b) 11 m/s c) 12 m/s d) 13 m/s

3) consider the motion diagram. it illustrates a car's velocity (v) and acceleration (a). the best description of a car’s velocity in this diagram is: a) a car’s velocity remained the same at 10 m/s. b) a car’s velocity decreased from 10 m/s to 5 m/s. c) a car increased its velocity from 5 m/s to 10 m/s. d) a car increased its velocity from -5 m/s to -1 m/s.

4) displacement is to velocity as is to acceleration. a) direction b) speed c) time d) velocity

5) ridge x moves a total of 25 cm in 5 years. what is its rate of movement, expressed in cm/year? a) 1/5 cm/year b) 5/25 cm/year c) 5/1 cm/year d) 1/25 cm/year

6) consider these four line graphs representing speed in meters/second, where each x-axis is labeled in seconds and each y-axis is labelled in meters. which graph represents an average speed of 1.57 m/s * hover over answer image to enlarge

7) a car's position in relation to time is plotted on the graph. what can be said about the car during segment b? a) the car travels for 80 seconds during segment b. b) the car has come to a stop and has zero velocity. c) the car is traveling faster during segment b than in segment c. d) the car is traveling with a constant velocity due to the flat line of the graph.

8) diego kicks a soccer ball from the end line. his fellow students time and mark the soccer ball as it moves down the field. the graph represents the ball's progress. based on the graph, during what time is the soccer ball not moving? a) from 0 to 1.5 seconds b) from 3.0 to 4.5 seconds c) from 4.5 to 5.0 seconds d) from 1.5 to 3.0 seconds

9) speed graph time (s) distance (m) 0 0 1 3 2 6 3 12 4 16 consider the data table charting the speed of a toy car moving across the floor. the line graph representing this data would best be described as a a) curved line with varying slope. b) diagonal line with a slope of 3. c) horizontal line with a slope of 3. d) diagonal line with varying slope, from 3 to 4.

10) a rock is whirled around in a circle with a slingshot. as the rock leaves the slingshot, it has an instantaneous velocity in a straight line. how do newton's laws of motion explain this? a) gravity does not exert a force on the rock until it leaves the slingshot. b) once the slingshot is not exerting a force on the rock it will slow down and stop. c) air resistance keeps the rock from moving in a circle after it leaves the slingshot. d) to move in a circle requires an acceleration and therefore a net force. this force is supplied by the slingshot.

11) using newton's law of gravity: f = gm1m2/d2 and fnet = ma, we can calculate the acceleration of a satellite. what will happen to the acceleration of a satellite if the mass and the distance from the center of the earth is doubled? a) the acceleration will not change. b) the acceleration will become 1/4 as much. c) the acceleration will become 1/2 as much. d) the acceleration will become twice as much.

12) the velocity of an object is equal to the distance divided by time. the equation is velocity = distance/time. if you wanted to calculate the time required for an object to travel a distance and you knew the velocity, you would a) multiply: velocity x distance. b) subtract: velocity – distance. c) divide: distance ÷ velocity d) add: velocity + distance

13) a kite is traveling in the sky at a velocity of 5 km h . if you are walking underneath the kite in the opposite direction at a rate of 3 km h , what is the kite's velocity relative to you on the ground? a) -8 km h b) -2 km h c) 5 km h d) 8 km h