KinematicsAverage Speed and Instantaneous Velocity (NEET (National Eligibility cum Medical Entrance Test) Physics): Questions 9  12 of 108
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Question number: 9
» Kinematics » Average Speed and Instantaneous Velocity
Question
An express train is moving with a velocity v _{1}. Its driver finds another train is moving on the same track in the same direction with velocity v _{2}. To escape collision, driver applies a retardation a on the train, the minimum time of escaping collision will be
Choices
Choice (4)  Response  

a.  t = 

b.  t _{1} = 

c.  t1 = tt1 

d.  All of the above 

Question number: 10
» Kinematics » Average Speed and Instantaneous Velocity
Question
Two particles move simultaneously from two points A and B, 300m apart. The particle at A starts towards B with a velocity of 25 m/s and that at B, moves normal to the former with a velocity of 20 m/s.
(1) The relative velocity of the particle at A, w. r. t. that at B is 32.02 m/s
(2) The relative velocity of the particle at A, w. r. t. that at B is 12.04 m/s
(3) They are closest to each other after 7.32 sec.
(4) They are closest to each other after 4.25 sec.
Choices
Choice (4)  Response  

a.  1 and 3 

b.  1, 2 and 3 

c.  2 and 4 

d.  1 and 2 

Passage
When an airplane flies, its total velocity with respect to the ground is v _{total} = v _{plane} + v _{wind’} where v _{plane} denotes the plane’s velocity through motionless air,
And v _{wind} denotes the wind’s velocity. Crucially, all the quantities in this equation are vectors. The magnitude of a velocity vector is often called the “speed. ”
Consider an airplane whose speed through motionless air is 100 meters per second (m/s). To reach its destination, the plane must fly east.
The “heading” of a plane is in the direction in which the nose of the plane points. So, it is the direction in which the engines propel the plane.
Question number: 11 (1 of 3 Based on Passage) Show Passage
» Kinematics » Average Speed and Instantaneous Velocity
Question
If the plane has an eastward heading, and a 20 m/s wind blows towards the southwest, then the plane’s speed is 
Choices
Choice (4)  Response  

a.  more than 100 m/s 

b.  more than 80 m/s but less than 100 m/s 

c.  80 m/s 

d.  100 m/s 

Question number: 12 (2 of 3 Based on Passage) Show Passage
» Kinematics » Average Speed and Instantaneous Velocity
Question
Let denote the answer of above question. The plane has what speed with respect to the ground?
Choices
Choice (4)  Response  

a. 


b.  (100 m/s) 

c.  (100 m/s) 

d. 

