33 Years NEET-AIPMT Chapterwise Solutions - Physics 2020

Motion in a Plane
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17
CHAPTER
4
Motion in a Plane
4.2 Scalars and Vectors
1. Identify the vector quantity among the following.
(a) Distance (b) Angular momentum
(c) Heat (d) Energy (1997)
4.4 Addition and Subtraction of Vectors-
Graphical Method
2. Six vectors, a through f have the magnitudes
and directions indicated in the figure. Which of the
following statements is true?
(a) b + c = f
(b)
d + c = f
(c) d + e = f
(d)
b + e = f (2010)
4.5 Resolution of Vectors
3. If a unit vector is represented by 05 . ^ i− 08 .
^ j + ck
^
then the value of c is
(a) 001 . (b) 011 .
(c) 1 (d) 039 . (1999)
4.6 Vector Addition-Analytical Method
4. If the magnitude of sum of two vectors is equal to
the magnitude of difference of the two vectors, the
angle between these vectors is
(a) 45° (b) 180°
(c) 0° (d) 90° (NEET-I 2016)
5. The vectors A and B
are such that | A+ B| = | A− B|
.
The angle between the two vectors is
(a) 45° (b) 90°
(c) 60° (d) 75° (2006, 1996, 1991)
6.
If | A+ B| = | A| + | B|
then angle between A and B
will be
(a) 90° (b) 120°
(c) 0° (d) 60°. (2001)
7. The magnitude of vectors AB , and C are 3, 4 and
5 units respectively. If A + B = C
, the angle between
A and B is
(a) p/2 (b) cos –1 (0.6)
(c) tan –1 (7/5) (d) p/4.(1988)
4.7 Motion in a Plane
8. The x and y coordinates of the particle at any time
are x = 5t – 2t 2 and y = 10t respectively, where x and
y are in metres and t in seconds. The acceleration of
the particle at t = 2 s is
(a) 5 m s –2 (b) –4 m s –2
(c) –8 m s –2 (d) 0 (NEET 2017)
9. The position vector of a particle R as a function of
time is given by R ^
^
= 4sin( 2πt) i+
4cos( 2π t)
j where
^ ^
R is in meters, t is in seconds and i and j denote
unit vectors along x-and y-directions, respectively.
Which one of the following statements is wrong for
the motion of particle?
(a) Magnitude of the velocity of particle is
8 p meter/second.
(b) Path of the particle is a circle of radius 4 meter.
(c) Acceleration vector is along −R.
2
v
(d) Magnitude of acceleration vector is , where v
is the velocity of particle.(2015) R
10. A particle is moving such that its position coordinates
(x, y) are (2 m, 3 m) at time t = 0, (6 m, 7 m) at time
t = 2 s and (13 m, 14 m) at time t = 5 s. Average
velocity vector ( v av ) from t = 0 to t = 5 s is
(a) 1 13 14
5 ( ^ ^
i + j ) (b) 7 3 ( ^ ^
i + j )
(c) 2( ^ ^
i + j)
(d) 11 5 ( i + j ) (2014)
11. A body is moving with velocity 30 m/s towards east.
After 10 seconds its velocity becomes 40 m/s towards
north. The average acceleration of the body is
^
^