11. (JEE Main 2021 (Online) 26th February
Evening Shift
)
A scooter accelerates from rest for time t1 at constant rate a1 and then retards at
constant rate a2 for time t2 and comes to rest. The correct value of
wil be :
A.
B.
C.
D.
Correct Option is (C)
From given information :
For 1st
interval
v0 = a1 t1
....... (1)
For 2nd
interval
v0 = a2 t2
..... (2)
from (1) & (2)
a1 t1 = a2
t2
12. (JEE Main 2021 (Online) 24th February
Morning Shift
)
If the velocity-time graph has the shape AMB, what would be the shape of the corresponding acceleration-time
graph?
A.
B.
C.
D.
Correct Option is (C)
From
the graph for first line, the slope is negative and intercept is positive.
So, equation
of line is
Similarly, for second line, the slope is
positive and intercept is negative, so equation of line is
The corresponding acceleration-time graph as shown
below
Hence,
option (a) is correct.
13. .(JEE Main 2021 (Online) 31st August Evening Shift
)
A particle is moving with constant acceleration 'a'. Following graph shows v2 versus
x(displacement) plot. The acceleration of the particle is ___________ m/s2.
Correct answer is (1)
y = mx + C
v2 =
x + 20
v2 = 2x +
20
2v =
2
a =
v = 1
14. (JEE Main 2020 (Online) 5th September
Evening Slot
)
The velocity (v) and time (t) graph of a body in
a straight line motion is shown in the figure.
The point S is at 4.333 seconds. The total
distance covered by the body in 6 s is :
A. 12 m
B. 11 m
C.
m
D.
m
Correct Option is (D)
4.333 sec =
sec
Distance = area under the v-t graph
= Area of Parallelogram + Area of triangle
=
+
=
m
15. (JEE Main 2020 (Online) 4th September
Morning Slot
)
A Tennis ball is released from a height h and after freely falling on a wooden floor
it rebounds and reaches height
. The
velocity versus height of the ball during its motion may be represented graphically by : (graph are
drawn schematically and on not to scale)
A.
B.
C.
D.
Correct Option is (C)
V, h curve will be parabolic.
Downward velocity is negative and upward is positive
When ball is coming down graph will be in IV quadrant and when going up graph will be in
I quadrant.