Mathematics
Grade-8
Easy
Question
Which story matches the graph below?
- Kevin took his dog for a walk. He started slowly but then increased his speed. Kevin sat on a bench while his dog played around in the park. Then, he realized it was getting late and walked home quickly.
- Kevin rode his bicycle up a really steep hill. At the top of the hill, the road flattened out. Then, he flew down the other side.
- Kevin went shopping with his mom. She slowly pulled out of the driveway and quickly approached the store. Kevin and his mom parked the car, quickly did their shopping, and went home.
- Kevin went for a run. He started off at a good pace and gained some speed until he ran out of breath. After catching his breath, Kevin decided to just walk home.
Hint:
In a distance-time graph, the slope or gradient of the line is equal to the speed of the object. The steeper the line (and the greater the gradient) the faster the object is moving. A horizontal line on a distance-time graph shows that the object is stationary (not moving because the distance does not change)
The correct answer is: Kevin took his dog for a walk. He started slowly but then increased his speed. Kevin sat on a bench while his dog played around in the park. Then, he realized it was getting late and walked home quickly.
The slope is positive in the first two segments. The second segment is steeper than the first, indicating an increase in speed. The flat line represents no rate of change and the time Kevin spends on the bench. Finally, as Kevin returns from the park, his distance from home decreases, which is represented by the final line segment by its negative slope. (A)
A distance-time graph shows how far an object has travelled in a given time
Distance is plotted on the Y-axis. Time is plotted on the X-axis.
In (0-3) time interval
Total distance is travelled 6 unit.
Total time = 3 unit
Speed = (distance ÷ time) = 6÷3 = 2 (it means slope positive, That is distance is increasing with increasing time.)
In ( 3-5 ) time interval
Total distance is travelled 8 unit.
Total time = 2 unit.
Speed= 8 ÷ 2 = 4 (Slope is positive.)
That is distance is increasing with increasing time.
In ( 12-20 ) interval Slope is negative and then time is increasing but distance is decreasing.
All point follow option A, Therefore Option A is correct.
Linear functions are first-degree functions that form a straight line when graphed; these functions have one or two variables and no exponents or powers.
Distance' is the total length travelled by an object. The standard unit is the 'metre'.
it is scalar quantity
Displacement' is the length between start and stop positions and includes a direction. Displacement is a vector quantity.
