Question

2. A car is moving on a straight road with a uniform acceleration. The follow
table gives the speed of the car at various instants of time.
Time(s)
Speed(ms)
0
5
10
10
20
15
30
20
40
25
50
30
(i)Draw the shape of speed-time graph representing the above sets of
observations.
(ii) Find the acceleration of the car.
(iii)When will you say a body is in uniform acceleration?​

Answer 1

Answer:

Given that,

A car is moving on a straight road with uniform acceleration.

Time = 0, 10, 20, 30, 40, 50

Speed = 5, 10, 15, 20, 25, 30

The slope of graph AB is called acceleration.

We need to calculate the acceleration of car

Using graph,

Acceleration = \dfrac{BC}{AC}Acceleration=

AC

BC

Put the value into the formula

Acceleration = \dfrac{30-5}{50-0}Acceleration=

50−0

30−5

Acceleration = \dfrac{25}{50}Acceleration=

50

25

Acceleration = \dfrac{5}{10}Acceleration=

10

5

Acceleration = 0.5\ m/s^2Acceleration=0.5 m/s

2

(II). We need to calculate the distance travelled by the car in 50 sec

Using graph

Distance traveled by truck = Area of trapezium OABD

D=\dfrac{1}{2}\times(AO+BD)\timesODD=

2

1

×(AO+BD)\timesOD

Put the value into the formula

D=\dfrac{1}{2}\times(5+30)\times50D=

2

1

×(5+30)×50

D= 875\ mD=875 m

Hence, (I) The acceleration of the car is 0.5 m/s²

(II). The distance travelled by the car in 50 sec is 875 m

Explanation:

Figure is in the picture