Resultant of two vectors and is of magnitude . If is reversed, then resultant is of magnitude . What is the value of ?
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Official Solution
Correct Option: (1)
Let be angle between and . Resultant of and is
When is reversed, then the angle between and is . Resultant of and is
Squaring and adding and , we get
02
PYQ 2012
medium
physicsID: amueee-2
What is approximately the centripetal acceleration (in units of acceleration due to gravity on earth, ) of an air-craft flying at a speed of through a circular arc of radius ?
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Official Solution
Correct Option: (1)
Here, , ,
Centripetal acceleration,
In the units of , the centripetal acceleration is .
03
PYQ 2013
medium
physicsID: amueee-2
Particle moves along the line with constant velocity v of magnitude and directed parallel to the positive -axis (see figure). Particle starts at the origin with zero speed and constant accelerationa (of magnitude ) at the same instant that the particle A passes the y axis. The angle between a and the positive axis that would result in a collision between these two particles should have a value equal to
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Official Solution
Correct Option: (1)
Given that For particle , and For particle Let particle are collide after . distance covered by in and For collision . Velocity of Now, from
04
PYQ 2015
medium
physicsID: amueee-2
A shell fired from a gun at sea level rises to a maximum height of when fired at a ship away. The muzzle velocity should be
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Official Solution
Correct Option: (4)
or
or Now,
05
PYQ 2015
medium
physicsID: amueee-2
From a building two balls and are thrown such that is thrown upwards and downwards with the same speed (both vertically). If and are their respective velocities on reaching the ground then,
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their velocities depend on their masses
Official Solution
Correct Option: (2)
Let the ball is thrown vertically upwards with speed and ball is thrown vertically downwards with the same speed . After reaching the highest point, comes back to its point of projection with the same speed in the downward direction. If be height of the building, then velocity of on reaching the ground is or
and that of on reaching the ground is or
From eqns. and , we get
06
PYQ 2016
hard
physicsID: amueee-2
Three particles and are at rest at the vertices of an equilateral triangle of side . Each of the particles starts moving with constant speed is moving along along and along . The particles will meet each other at time given by
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Official Solution
Correct Option: (4)
The velocity component towards centroid of triangle
Distance of altitude
Time
07
PYQ 2016
medium
physicsID: amueee-2
The expression of the trajectory of a projectile is given as , where and are respectively the vertical and horizontal displacements and and are constants. The time of flight of the projectile is