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Champ Jee
Subject: Physics
, asked on 13/5/18
Solve:
Q50. What is the angle between
A
→
and the resultant of
(
A
→
+
B
→
)
a
n
d
(
A
→
-
B
→
)
?
(1) 0
°
(2)
tan
-
1
A
B
(3)
tan
-
1
B
A
(4)
tan
-
1
A
-
B
A
+
B
Answer
3
Champ Jee
Subject: Physics
, asked on 12/5/18
Q9.
Ans: option(c).
Q.9. If the resultant of n forces of different magnitudes acting at a point is zero, then the minimum value of n is
(a) 1
(b) 2
(c) 3
(d) 4
Answer
2
Champ Jee
Subject: Physics
, asked on 12/5/18
Q13.
Ans (b). How? Please also explain the question about what it's asking!:
13
·
A
vector
a
→
is
truned
without
achange
in
its
length
through
a
small
angle
dθ
·
The
value
of
△
a
→
and
△
a
are
repectively
.
(
a
)
0
,
a
dθ
b
a
dθ
,
0
c
0
,
0
d
None
of
these
Answer
1
Champ Jee
Subject: Physics
, asked on 11/5/18
Q2.
Ans: a,b
How do we find perpendicular components? Please explain.
Q2. Given two vectors
A
→
=
=
3
i
^
+
4
j
^
and
B
→
=
=
i
^
+
j
^
,
θ
is the angle between
A
→
and
B
→
. Which of the following statement is/ are correct?
a
.
A
→
cos
θ
i
+
j
2
is
the
component
of
A
→
along
B
→
.
b
.
A
→
sin
θ
i
-
j
2
is
the
component
of
A
→
perpendicular
to
B
→
c
.
A
→
cos
θ
i
-
j
2
is
the
component
of
A
→
along
B
→
.
d
.
A
→
sin
θ
i
+
j
2
is
the
component
of
A
→
perpendicular
to
B
→
Answer
1
Champ Jee
Subject: Physics
, asked on 11/5/18
Illustration 3.20 An inclined plane is inclined at with horizontal as shown in Fig. 3.39. Write a unit vector in the direction parallel
a
^
and perpendicular
b
^
to inclined plane, in standard xy coordinate system.
Answer
1
Champ Jee
Subject: Physics
, asked on 11/5/18
(b) part.
Illustration 3.1.
A car is moving round a circular track with a constant speed v of 20
m
s
-
1
(as shown in Fig. 3.12). At different times, the car is at A, B and C, respectively. Find the velocity change (a) from A to C, and (b) from A to B.
Answer
2
Champ Jee
Subject: Physics
, asked on 11/5/18
Q.4. Figure shows regular hexagon PQRSTU. Find the value of
P
Q
¯
+
P
R
¯
+
P
S
¯
+
P
T
¯
+
P
U
¯
.
(A)
P
O
¯
(B) 2
P
O
¯
(C) 4
P
O
¯
(D) 6
P
O
¯
Answer
1
Champ Jee
Subject: Physics
, asked on 9/5/18
Help.:
Q. Figure shows vector
A
⇀
and four other vectors that have the same magnitude but differ in orientation. The vectors which have the same dot product with
A
⇀
are:
i
B
⇀
a
n
d
C
⇀
i
i
D
⇀
a
n
d
E
⇀
(
i
i
i
)
D
⇀
a
n
d
C
⇀
(
i
v
)
B
⇀
a
n
d
E
⇀
(A) (i) and (ii) (B) (i) and (iii)
(C) (ii) and (iv) (D) (iv) and (iii)
Answer
3
Champ Jee
Subject: Physics
, asked on 5/5/18
Q38.
Ans: A,D.
How? Also, explain why other options are wrong.
Answer
2
Champ Jee
Subject: Physics
, asked on 4/5/18
A vector
A
→
of length 10 units makes an angle of 60° with the vector
B
→
of length 6 units. Find the magnitude of the vector difference
A
→
–
B
→
& the angle is makes with vector
A
→
.
Answer
1
Champ Jee
Subject: Physics
, asked on 3/5/18
Q21. Ans key: B,D. How??
21
.
T
h
e
v
a
l
u
e
o
f
A
→
+
B
→
-
C
→
+
D
→
c
a
n
b
e
z
e
r
o
i
f
:
-
A
A
→
=
5
,
B
→
=
3
,
C
→
=
4
,
D
→
=
13
A
A
→
=
2
2
,
B
→
=
2
,
C
→
=
2
,
D
→
=
5
C
A
→
=
2
2
,
B
→
=
2
,
C
→
=
2
,
D
→
=
10
D
A
→
=
5
,
B
→
=
4
,
C
→
=
3
,
D
→
=
8
Answer
1
Champ Jee
Subject: Physics
, asked on 3/5/18
Q4.
Ans: option(C). I solved this question but I myself didn't understand that can I apply by methods? Is it valid?
I have joined it in answer.
Answer
2
Champ Jee
Subject: Physics
, asked on 1/5/18
Q5.
Ans : 100 s.
Q.5. A bird is at a point P (4, - 1, - 5) and sees two points
P
1
(- 1, - 1, 0) and
P
2
(3, - 1, - 3). At time t = 0, it starts flying with a constant speed of 10 m/s to be in line with points
P
1
and
P
2
in minimum possible time t. Find t, if all coordinates are in kilometers.
Answer
1
Champ Jee
Subject: Physics
, asked on 30/4/18
Que in pic!
No links pls.
Solve & explain briefly
Q. Three vectors each of magnitude A are acting at a point such that angle between any two consecutive vectors in same plane is 60
°
. The magnitude of their resultant is
(a) 2 A
(b) 2 A
(c) 3 A
(d) 6 A
Answer
1
Champ Jee
Subject: Physics
, asked on 29/4/18
Ans: option(c).
How??
Q11. A body moves in anticlockwise direction on a circular path in the x- y plane. The radius of the circular path is 5 m and its centre is at the origin. In a certain interval of time, displacement of the body is observed to be 6 m in the positive y-direction. Which of the following is true?
(A) Its initial position vector is 5
i
^
m. (B) Its initial position vector is
-
3
i
^
+
4
j
^
m.
(C) Its final position vector is
4
i
^
+
3
j
^
(D) Its final position vector is 6
j
^
m.
Answer
1
1
2
3
4
5
Next
What are you looking for?
Q50. What is the angle between and the resultant of
(1) 0 (2)
(3) (4)
Ans: option(c).
Q.9. If the resultant of n forces of different magnitudes acting at a point is zero, then the minimum value of n is
(a) 1
(b) 2
(c) 3
(d) 4
Ans (b). How? Please also explain the question about what it's asking!:
Ans: a,b
How do we find perpendicular components? Please explain.
Q2. Given two vectors is the angle between . Which of the following statement is/ are correct?
Illustration 3.1. A car is moving round a circular track with a constant speed v of 20 (as shown in Fig. 3.12). At different times, the car is at A, B and C, respectively. Find the velocity change (a) from A to C, and (b) from A to B.
(A)
(B) 2
(C) 4
(D) 6
Q. Figure shows vector and four other vectors that have the same magnitude but differ in orientation. The vectors which have the same dot product with are:
(A) (i) and (ii) (B) (i) and (iii)
(C) (ii) and (iv) (D) (iv) and (iii)
Ans: A,D.
How? Also, explain why other options are wrong.
Ans: option(C). I solved this question but I myself didn't understand that can I apply by methods? Is it valid?
I have joined it in answer.
Ans : 100 s.
Q.5. A bird is at a point P (4, - 1, - 5) and sees two points (- 1, - 1, 0) and (3, - 1, - 3). At time t = 0, it starts flying with a constant speed of 10 m/s to be in line with points and in minimum possible time t. Find t, if all coordinates are in kilometers.
No links pls.
Solve & explain briefly
Q. Three vectors each of magnitude A are acting at a point such that angle between any two consecutive vectors in same plane is 60. The magnitude of their resultant is
(a) 2 A
(b) 2 A
(c) 3 A
(d) 6 A
How??
Q11. A body moves in anticlockwise direction on a circular path in the x- y plane. The radius of the circular path is 5 m and its centre is at the origin. In a certain interval of time, displacement of the body is observed to be 6 m in the positive y-direction. Which of the following is true?
(A) Its initial position vector is 5 m. (B) Its initial position vector is m.
(C) Its final position vector is (D) Its final position vector is 6 m.