The displacement of a particle is given by y=a+bt+ct2-dt4. The initial velocity and initial acceleration, respectively, are: (\(Given: v=\frac{dx}{dt}~and~a=\frac{d^2x}{dt^2}\))
b, -4d
-d, 2c
b, 2c
2c, -4d
The momentum is given by p=4t+1, the force at t=2s is-[Given: F=dPdt]
() 4 N
() 8 N
() 10 N
() 15 N
If the momentum of a particle is given by P=(180-8t) kg m/s, then its force will be-[Given: F=dPdt]
Zero
8 N
-8 N
4 N
If fx=x2-2x+4, then f(x) has:
a minimum at x=1.
a maximum at x=1.
no extreme point.
no minimum.
A particle is moving along x-axis. The velocity v of particle varies with its position x as v=1x. Find velocity of particle as a function of time t given that at t=0, x=1 .
v=2t+1
v=12t+1
v=1t
None of these
A vector A→ is directed along 30° west of north direction and another vector B→ along 15° south of east. Their resultant cannot be in ____________ direction.
North
East
North-East
South
ABCD is a quadrilateral. Forces BA→, BC→, CD→ & DA→ act at a point. Their resultant is
() 2 AB→
() 2 DA→
() zero vector
() 2 BA→
The maximum and minimum magnitude of the resultant of two vectors are 17 units and 7 units respectively. Then the magnitude of resultant of the vectors when they act perpendicular to each other is:
14
16
18
13
A vector A→ makes an angle of 20° and B→ makes an angle of 110° with the X-axis. The magnitudes of these vectors are 3 m and 4 m respectively. Find the magnitude of the resultant.
() 1
() 52
() 5
() 7
A particle is moving westward with a velocity v→i=5 m/s. Its velocity changed to v→f=5m/s northward. The change in velocity vector ∆V→=v→f-v→i is:
52 m/s towards north east
5 m/s towards north west
zero
52 m/s towards north west
Consider east as positive x-axis, north as positive y-axis and vertically upward direction as z-axis. A helicopter first rises up to an altitude of 100 m than flies straight in north 500 m and then suddenly takes a turn towards east and travels 1000 m east. What is position vector of helicopter. (Take starting point as origin)
1000 i^-500 j^+100 k^
1000 i^+500 j^-100 k^
1000 i^+500 j^+100 k^
-1000 i^+500 j^+100 k^
A force F→=6i^-8j^+10k^ Newton produces acceleration 1 m/s2 in a body. The mass of the body is (in kg)
6i^-8j^+10k^
100
102
10
Given the vectors
A→=2i^+3j^-k^ B→=3i^-2j^-2k^& C→=pi^+pj^+2pk^
Find the angle between A→-B→ & C→
(A) θ=cos-123
(B) θ=cos-132
(C) θ=cos-123
(D) none of these
The vector having a magnitude of 10 and perpendicular to the vector 3i^-4j^ is-
4i^-3j^
52 i^-52 j^
8i^+6j^
8i^-6j^
A force F→=3i^+cj^+2k^ acting on a particle causes a displacement d→=-4i^+2j^+3k^. If the work done is 6J then the value of 'c' is- [Given: W=F.→d→]
() 12
() 0
() 6
A particle moving along a straight line according to the law x=At+Bt2+Ct3, where x is its position measured from a fixed point on the line and t is the time elapsed till it reaches position x after starting from the fixed point. Here A, B and C are positive constants.
Its velocity at t=0 is A
Its acceleration at t=0 is B
Its velocity at t=0 is B
Its acceleration at t=0 is C
If the velocity of a particle moving on x-axis is given by v=3t2-12t+6. At which time is the acceleration of particle zero?
2 sec
2+2 sec
2-2 sec
Momentum of a body moving in a straight line is p=t2+2t+1 kg m/s. Find the force acting on a body at t=2 sec
6 N
2 N
A particle moves along straight line such that at time t its position from a fixed point O on the line is x=3t2-2. The velocity of the particle when t=2 is:
() 8 ms-1
() 4 ms-1
() 12 ms-1
Coordinates of a moving particle are given by x=ct2 and y=bt2. The speed of the particle is given by
2t c+b
2t c2-b2
t c2+b2
2t c2+b2
The x and y components of vector A→ are 4m and 6m respectively. The x, y components of vector A→+B→ are 10m and 9m respectively. The length of B→ is ______ and angle that B→ makes with the x axis is given by _______.
(A) 0.45m, tan-11/2
(B)&nsp; 4.5m, tan-11/2
(C) 45m, tan-11/2
(D) 45m, tan-11/2
A particle travels with speed 50 m/s from the point (3, 7) in a direction 7i^-24j^. Find its position vector after 3 seconds.
() 151i^+45j^
() 45i^-137j^
() 4.5i^-151j^
If a→ is a vector and x is a non-zero scalar, then which of the following is correct?
If θ is the angle between two vectors a→ and b→, and |a→×b→|=a→.b→, then θ is equal to:
0°
180°
135°
45°
The vector b→, which is collinear with the vector a→=(2, 1, -1) and satisfies the condition a→.b→=3 is-
(1, 1/2, -1/2)
(2/3, 1/3, -1/3)
(1/2, 1/4, -1/4)
(1, 1, 0)
If a, b and c are three non-zero vectors such that a→+b→+c→=0, then the value of a→.b→+b→.c→+c→.a→ will be:
Less than zero
equal to zero
greater than zero
3
Two vectors a→ and b→ inclined at an angle θ w.r.t. each other have a resultant c→ which makes an angle β with a→. If the directions of a→ and b→ are interchanged, then the resultant will have the same
(A) mgnitude
(B)&nsp; direction
(C) magnitude as well as diretion
(D) neither magnitue nor direction
Two vectors A→ and B→ lie in a plane. Another vector C→ lies outside this plane. The resultant A→+B→+C→ of these three vectors
can be zero
cannot be zero
lies in the plane of A→ &B→
lies in the plane of A→ & A→+B→
The vector sum of the forces of 10 N and 6 N can be
18 N
20 N
A set of vectors taken in a given order gives a closed polygon. Then the resultant of these vectors is a
scalar quantity
pseudovector
unit vector
null vector
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