motion graph

what is the speed of the motion from D to E 

• 20 m/s
• 40 m/s
• 0 cm/s
• 200m/s

what is the position at 10th second

• 0 m
• 10 m
• 20 m
• 30 m

from 3rd second to 5th second, the object is

• moving at a constant speed
• speeding up
• not moving
• slowing down

from 1st second to 3rd second, the speed is

• constant
• increasing
• 0 
• decreasing

when the line is flat, what is constant?

• speed
• position
• time
• speed and position

which one is increasing?

• speed
• position
• time and speed
• time and distance

when happened during the last second?

• slowing down
• moving backward and slowing down
• moving backward at a constant speed
• none of these

At what time the object was back to the starting point?

• 5th second
• 10th second
• 8th second
• 25th second

At what time the object made a U-turn?

• 5th second
• 10th second
• 25th second
• 5th and 25th second

when did the object stayed still?

• first 10 seconds
• first 20 seconds
• 20th ~30th seconds
• 30th~40th seconds