Physics - Description of Motion in Two and Three Dimension
Exam Duration: 45 Mins Total Questions : 30
Which of the statements given below are correct?
The statements :
A.The direction of the velocity of a body can change when its acceleration is constant.
B.A body can have a constant velocity and still have a varying speed.
C.A body can have a constant speed and still have a varying velocity.
D.A body can have zero velocity and still be acceleration.
- (a)
A and B only
- (b)
B and C only
- (c)
A,C and D only
- (d)
C and D only
A steel ball is bouncing up and down on a steel plate with a period of oscillation of 1 second.If g = 10 ms-2 , then it bounces upto height of
- (a)
5 cm
- (b)
10 cm
- (c)
2.5 m
- (d)
1.25 m
The average acceleration vector for a particle having a uniform circular motion is [r = radius of circle].
- (a)
a constant vector of the magnitude \(\frac{\sqrt2}{r}\)
- (b)
a null vector
- (c)
a vector of magnitude \(\frac{\sqrt2}{r}\) directed normal to the plane of the given uniform circular motion
- (d)
equal to the instantaneous acceleration vector
If retardation produced by air resistance is g/10, then time of flight of projectile will nearly
- (a)
Increases by 1%
- (b)
decreases by 1%
- (c)
remain same
- (d)
decreases by 2%
A person can throw a stone to a maximum distance of 100 m. The greatest height to which he can throw the stone is:
- (a)
100m
- (b)
75m
- (c)
50m
- (d)
25m
An arrow is shot into the air. Its range is 200 metres and its time of flight is 5 sec. If the value of g is assumed to be 10 m/sec2, then the horizontal component of the velocity of arrow is:
- (a)
25m/s
- (b)
40m/s
- (c)
31.25m/s
- (d)
12.5m/s
The equation of motion of a projectile is:
\(y=12x-{3\over 4}x^2\)
The horizontal component of velocity is 3 ms -1.Given that g = 10 ms -2 , what is the range of the projectile?
- (a)
12.4 m
- (b)
21.6 m
- (c)
30.6 m
- (d)
36.0 m
A rifle shoots a bullet with a muzzle velocity of 400 m/sec at a small target 400 metre away. The height above the target at which the bullet must be aimed to hit the target is:
- (a)
1 metre
- (b)
5 metre
- (c)
10 metre
- (d)
0.5 metre
A projectile is projected with kinetic energy K. If it has the 0.25 Kmaximum possible horizontal range, then its kinetic energy at the highest point will be:
- (a)
0.25 K
- (b)
0.5 K
- (c)
0.75 K
- (d)
1.0 K
To hit a target, the shooter should point his gun
- (a)
slightly lower than the target
- (b)
along the direction of target
- (c)
slightly higher than the target
- (d)
slightly sideways
A plane is flying horizontally at 98 m/s and releases an object which reaches the ground in 10 sec. The angle made by it while hitting the ground is:
- (a)
55°
- (b)
45°
- (c)
60°
- (d)
75°
A cricketer can throw a ball to a maximum horizontal distance of 100 m. The speed with which he throws the ball
- (a)
30 ms-1
- (b)
42 ms-1
- (c)
32 ms-1
- (d)
35 ms-1
A particle is projected upon an inclined plane with initial speed v = 20 m/s at an angle θ = 30° with the plane. The component of its velocity perpendicular to the plane when it strikes the plane is
- (a)
10√3 m/s
- (b)
10m/s
- (c)
5√3 m/s
- (d)
data is insufficient
After one second the velocity of a projectile makes an angle of 45° with the horizontal. After another one second it is travelling horizontally. The magnitude of its initial velocity and angle of projection are:
- (a)
14.62 m/s, 60°
- (b)
14.62 m/s,tan-1I (2)
- (c)
22.36 m/s, tan-1 (2)
- (d)
22.16 m/s, 60°
When a mass is rotating in a plane about a fixed point, its angular momentum is directed along:
- (a)
the radius
- (b)
the tangent to the orbit
- (c)
a line perpendicular to the plane of rotation
- (d)
none of the above
A particle covers equal distance around a circular path, in equal intervals of time. Which of the following quantities connected with the motion of the particle remains constant with time
- (a)
Displacement
- (b)
Velocity
- (c)
Speed
- (d)
Acceleration
If a person can throw a stone to maximum height of h metre vertically, then the maximum distance through which it can be thrown horizontally by the same person is :
- (a)
h/2
- (b)
h
- (c)
2h
- (d)
3h
The tangential component of acceleration of a particle in circular motion is due to
- (a)
speed of the particle
- (b)
change in the direction of velocity
- (c)
change in the magnitude of velocity
- (d)
rate of change of acceleration
If the equation for the displacement of a particle moving on a circular path is given by:
θ=2t3+0.5
where θ is in radian and t in second, then the angular velocity of the particle is:
- (a)
8 rad/sec
- (b)
12 rad/sec
- (c)
24 rad/sec
- (d)
36 rad/sec
At any instant a projectile is moving with velocity u in a direction making an angle α with horizon. After what time the direction of motion turns through an angle θ?
- (a)
\(u\ cos\theta\over g\ sin\ (\theta-\alpha)\)
- (b)
\(u\ sin\theta\over g\ cos\ (\theta-\alpha)\)
- (c)
\(u\over g\ sin\ (\theta-\alpha)\)
- (d)
\(u\over g\ cos\ (\theta-\alpha)\)
Two bodies are projected from ground with equal speeds 20 rnIs from the same position in same vertical plane to have equal range but at different angle above the horizontal. If one of the angle is 30°, the sum of their maximum heights is:
- (a)
400 m
- (b)
20 m
- (c)
30 m
- (d)
40 m
A particle is projected with velocity \(\sqrt{2gh}\) such that it just crosses two walls of height h and separated by h. Find the angle of projection.
- (a)
15°
- (b)
75°
- (c)
60°
- (d)
30°
Two cars of masses ml and m2 are moving in circles of radii r1 and r2 respectively. Their speeds are such that they make complete circles in the same time t. The ratio of their centripetal acceleration is :
- (a)
m1r1:m2r2
- (b)
m1:m2
- (c)
r1:r2
- (d)
1:1
The range of a projectile fired at an angle of 15° is 50 m. If it is fired with the same speed at an angle of 45°, its range will be:
- (a)
50 m
- (b)
100m
- (c)
25m
- (d)
37m
A motorcyclist going round in a circular track at a constant speed has:
- (a)
constant linear velocity
- (b)
constant acceleration
- (c)
acceleration of constant magnitude with its direction changing
- (d)
constant force
A particle describes uniform circular motion in a circle of radius 2 m, with the angular speed of 2 rad s-1. The magnitude of the change in its velocity in \(\frac{\pi}{2}\)s is:
- (a)
0 ms-1
- (b)
2√2 ms-1
- (c)
8 ms-1
- (d)
4 ms-1
- (e)
4√2 ms-1
A particle is projected under gravity with velocity √2ag from a point at a height h above the level plane at an angle θ to it. The maximum range R on the ground is:
- (a)
\(\sqrt{(a^2+1)h}\)
- (b)
\(\sqrt{a^2h}\)
- (c)
\(\sqrt{ah}\)
- (d)
\(2\sqrt{a(a+h)}\)