The graph given below shows how the speed of a car changes with time: What is the initial speed of car?

From the graph, it is clear that the car starts with a speed of 10 km h - 1 which is its initial speed at A . Note:- The initial speed of the car for the motion represented in the graph is the speed recorded at the time t = 0 h .

The graph given below shows how the speed of a car changes with time: What is the maximum speed attained by the car?

As shown in the graph, the maximum speed attained by the car is 35 kmh - 1 . Note:- The maximum speed is represented by the point B from where the car maintains the speed till the point C . Speed is defined as the distance covered per unit time.

The graph given below shows how the speed of a car changes with time: Which part of the graph shows zero acceleration?

The part of the graph represented by BC shows that the velocity of the car remains the same and hence the acceleration is zero. Note:- The part of the graph represented by BC is parallel to the time axis and hence its slope is zero. Thus, the acceleration of the car is also zero.

The graph given below shows how the speed of a car changes with time: Which part of the graph shows varying retardation?

The part of the graph represented by CD is showing the motion of the car with varying retardation. Note:- Here, the part of the graph represented by CD is not a straight line rather a curve which means that the speed is not changing uniformly. Moreover, the speed of the car was higher at point C and it decreases later becomes zero by the time it reaches the point D . Hence, the part CD shows the motion of the car with varying retardation.

The graph given below shows how the speed of a car changes with time: Find the distance travelled in the first eight hours.

The distance for the first eight hours can be obtained by calculating the area under the graph from point A to point C . The graph can be divided into two parts here. Those are trapezium OABM and rectangle MBCN . The distance covered by the object can be obtained by adding the areas of trapezium and rectangle. Thus, the distance travelled by car is given by s = Area of trapezium OABM + Area of rectangle MBCN . Area of a trapezium = 1 2 × (sum of parallel sides) × height. Area of rectangle = Length × breadth. Now, area of trapezium OABM = OA + BM 2 × OM = 10 + 35 2 × 3 = 67 . 5 km . Similarly, area of rectangle MBCN = BM × MN = 35 × 5 = 175 km . Therefore, the distance travelled by car is s = 67 . 5 + 175 = 242 . 5 km . Hence, in the first eight hours, the car travels 242 . 5 km .