Science
(a) A driver of a car travelling at 52 kmh-1 applies the brakes. Shade the area on the graph that represents the distance travelled by the car during the period.
(b) Which part of the graph represents uniform motion of the car?
Answer
(a) The initial speed of the car is 52 kmh-1. After the driver applies the brakes, the speed becomes zero.
The x-axis of the graph represents the time and the y-axis of the graph represents the velocity.
In the graph, point B represents the initial velocity of the car, that is, 52 kmh-1, and point T represents the time when the velocity becomes zero.
The distance travelled by an object is equal to the product of velocity and time.
Therefore, the area under the velocity-time graph represents the distance travelled by the car during the period as shown below :
Distance travelled by the car = Area of triangle BST.
(b) As the slope of portion AB is constant which means velocity is constant during this portion and hence portion AB represents the portion of uniform motion.
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