a driver of a car travelling at 52 km hour applies the brakes and accelerates uniformly in the opposite direction the car stops in 5 seconds. another driver going get 3 km hour in another car applies is break slowly and stop in 10 seconds on the same graph paper what the speed versus time graph for the two cars which of the following car travel for the after the brakes were applied
Share
Answer:
search-icon-header
Search for questions & chapters
search-icon-image
Use appLogin
Standard IX
Physics
NCERT
Speed / Velocity Time Graphs
Question
A driver of a car travelling at
52
km
h
−
1
applies the brakes and accelerates uniformly in the opposite direction. The car stops in
5
s. Another driver going at
3
km
h
−
1
in another car applies his brakes slowly and stops in
10
s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?
Open in AppOpen_in_app
Solution
appImg
Verified by Toppr
(A) : Initial speed of the car A
u
=
52
k
m
h
−
1
=
52
×
5
18
=
14.44
m
s
−
1
The car stops in 5 seconds i.e
v
=
0
at
t
=
5
(A) : Initial speed of the car A
u
=
3
k
m
h
−
1
=
3
×
5
18
=
0.83
m
s
−
1
The car stops in 10 seconds i.e
v
=
0
at
t
=
10
With the help of these initial and final points for both the cases, we can plot the graph of speed vs time.
Area under the speed-time graph gives the distance covered.
∴
Distance covered by car A
x
A
=
1
2
×
14.44
×
5
=
36.1
m
∴
Distance covered by car A
x
B
=
1
2
×
0.83
×
10
=
4.15
m
Thus car A travels more distance than B.
Initial speed of the car A
u
=
52
k
m
h
−
1
=
52
×
5
18
=
14.44
m
s
−
1
The car stops in 5 seconds i.e
v
=
0
at
t
=
5
(A) : Initial speed of the car A
u
=
3
k
m
h
−
1
=
3
×
5
18
=
0.83
m
s
−
1
The car stops in 10 seconds i.e
v
=
0
at
t
=
10
With the help of these initial and final points for both the cases, we can plot the graph of speed vs time.
Area under the speed-time graph gives the distance covered.
∴
Distance covered by car A
x
A
=
1
2
×
14.44
×
5
=
36.1
m
∴
Distance covered by car A
x
B
=
1
2
×
0.83
×
10
=
4.15
m
Thus car A travels more distance than B.
491418_464645_ans.png
Was this answer helpful?
upvote
27
mid-banner-image
SIMILAR QUESTIONS
star-struck
Q1
A car is travelling with a speed of 36km/h. The driver applies brakes retards the car uniformly. The car is stopped in 5seconds. Find the retardation of the car and the distance travelled before it is stopped.
View Solution
Q2
A van is travelling at 52 km/h, when brakes are applied it comes to rest in 5 s. Another van is travelling at 3 km/h and when brakes are applied it comes to rest in 10 s. Plot the speed versus time graph and calculate the braking distance for both the vans? [3 MARKS]
View Solution
Q3
A car moving at a constant speed of
54
k
m
/
h
comes to rest in
2.5
s
e
c
o
n
d
s
. The car covers
5
m
after driver applies the brakes. The total force applied to stop the car is
1000
N
. Calculate the power dissipated in stopping the car.
View Solution
Q4
A car is moving in a straight line with speed
18
k
m
h
−
1
. It is stopped in
5
s
by applying the brakes. The speed of car after 2 s of applying the brakes is:
View Solution
Solve