Question

4. A driver of a car A travelling at a uniform speed of 54 km/h for 10 s applies the brakes and decelerates uniformly.
The car stops in 5 s. Driver of car B going at 36 km/h for 10 s applies the brakes slowly and stops after 10 seconds.
Plot the speed-time graph of both cars and find out which of the two cars travelled farther after the brakes were applied?​

Answer 1

Answer:

B travelled farther than car A

Explanation:

Speed of A=54km/h

=15m/s

Speed of B= 36km/h

=10m/s

After plotting the graphs,

Distance travelled by A= 1/2*15*5 m

= 37.5 m

Distance travelled by B= 1/2*10*10 m

= 50 m

conclusion: B travelled farther than A (after applying brakes).

Answer 2

Answer:

here speed of car A =54 km / h

so here first we convert it into m/s i. e, 54×5/18=15 m/s.

now, we convert speed of car B i. e, 36×5/18=10m/s.

By plotting graph we can say:

Car A =1/2×15×5=37.5 m

Car B =1/2×10×10=50 m

Therefore, we can say that car B travelled farther.