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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 t 1 t 2 wil be :

A. a 1 + a 2 a 2

B. a 1 + a 2 a 1

C. a 2 a 1

D. a 1 a 2

Correct Option is (C)

JEE Main 2021 (Online) 26th February Evening Shift Physics - Motion Question 95 English Explanation
From given information :

For 1st interval

a 1 = v 0 t 1

v0 = a1 t1 ....... (1)

For 2nd interval

a 2 = v 0 t 2

v0 = a2 t2 ..... (2)

from (1) & (2)

a1 t1 = a2 t2

t 1 t 2 = a 2 a 1

   

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?

JEE Main 2021 (Online) 24th February Morning Shift Physics - Motion Question 99 English

A. JEE Main 2021 (Online) 24th February Morning Shift Physics - Motion Question 99 English Option 1

B. JEE Main 2021 (Online) 24th February Morning Shift Physics - Motion Question 99 English Option 2

C. JEE Main 2021 (Online) 24th February Morning Shift Physics - Motion Question 99 English Option 3

D. JEE Main 2021 (Online) 24th February Morning Shift Physics - Motion Question 99 English Option 4

Correct Option is (C)

JEE Main 2021 (Online) 24th February Morning Shift Physics - Motion Question 99 English Explanation 1
From the graph for first line, the slope is negative and intercept is positive.

So, equation of line is

v = m t + c

a 1 = d v d t = m

Similarly, for second line, the slope is positive and intercept is negative, so equation of line is

v = m t c

a 2 = d v d t = m

The corresponding acceleration-time graph as shown below

JEE Main 2021 (Online) 24th February Morning Shift Physics - Motion Question 99 English Explanation 2
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.

JEE Main 2021 (Online) 31st August Evening Shift Physics - Motion Question 70 English

Correct answer is (1)

y = mx + C

v2 = 20 10 x + 20

v2 = 2x + 20

2v d v d x = 2

a = v d v d x = 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 : JEE Main 2020 (Online) 5th September Evening Slot Physics - Motion Question 101 English

A. 12 m

B. 11 m

C. 49 4 m

D. 37 3 m

Correct Option is (D)

4.333 sec = 13 3 sec

Distance = area under the v-t graph

= Area of Parallelogram + Area of triangle

= 1 2 ( 4 ) ( 13 3 + 1 ) + 1 2 ( 6 13 3 ) × 2

= 37 3 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 h 2 . 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. JEE Main 2020 (Online) 4th September Morning Slot Physics - Motion Question 107 English Option 1

B. JEE Main 2020 (Online) 4th September Morning Slot Physics - Motion Question 107 English Option 2

C. JEE Main 2020 (Online) 4th September Morning Slot Physics - Motion Question 107 English Option 3

D. JEE Main 2020 (Online) 4th September Morning Slot Physics - Motion Question 107 English Option 4

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.

At H = h, v = 0

at h = 0, v = 2 g h

also a = –g, throughout this motion.