Motion, Force & Newton's Law of Motion

The average speed of a car is 35 km/h. How far can it travel in 45 minutes?

• 129 km

• 467 km

• 0.78 km

• 26.25 km

Anna rides her bike toward ice cream shops which is 8 km away from her house, this journey takes time about 3 hours. After she gets ice cream, she starts riding toward Mary's house which 2 km away from ice cream shop, and its journey takes another 1 hour. What is the average speed of Anna's entire journey?

This distance-time graph represents the motion of the man walking at the straight path. At what interval of time the man moves forward with constant speed?

Look at distance - time graph of man walking at the straight path. At interval of 5 s - 15 s the man . . .

• moves forward with constant velocity

• moves backward with constant velocity

• does not move

• moves backward with constant acceleration

The movement of an object is recorded at this following distance-time graph. When does the object move backward?

• at 0 - 1 s

• at 2 - 4 s

• at 4 - 8 s

• all the time

The motion of four reptiles: Comodo dragon, Black mamba, Six-lined racerunner and Costa rican spiny-tailed Iguana are recorded in the distance-time graph (figure 1), each colored-line shows the motion of each reptile. According to the graph, what is the slowest reptile?

• Black mamba

• Comodo dragon

• Six-lined racerunner

• Costa rican spiny-tailed iguana

What action of these following probably involving contact force?

• negative electric charge attract to positive electric charge

• gravitational force pulls fallen leaves

• stretching a rubber band

• attracting iron nail by a magnet

what is the name of force acts on the object shown by letter B?

• tension

• friction

• gravitational force

• normal force

The following picture shows a boy who sliding down the ice hill on his board. There are three forces act the board represented by letter a, b and c. Which force is called the normal force?

• a

• b

• c

• a and b

Look at the picture. The initial position of the spring is labelled by A and the condition when it is stretched is laballed by B. What is the direction of the spring force?

• It directs to the right

• It directs to the left

• It is pointing upward

• It is pointing downward