The x and y coordinates of a particle moving in a plane are given be x(t) = acos(pt) and y(t) = bsin(pt) where a, b (<a) and p are positive constants of appropriate dimensions and t is time. Then , which of the following is not true?
The path of the particle is an ellipse
Velocity and acceleration of the particle are perpendicular to each other at t = π/2p
Acceleration of the particle is always directed towards a fixed point
Distance travelled by the particle in the time interval between t = 0 and t = π/2p is a
A stick of length L and mass M lies on a frictionless horizontal surface on which it is free to move in any way. A ball of mass m moving with speed V collides elastically with the stick as shown in fig below. If after the collision, the ball comes to rest, then what should be the mass of the ball?
m = 2M
m = M
m= M/2
m = M/A
A man is at height of 100 m. he sees a car which makes an angle of with man's position. If the car moves to a point where angle is what is the distance moved by it?
The maximum range of a gun on horizontal terrain is 16 km if g=10m/s2. What must be the muzzle velocity of the shell?
200 m/s
100 m/s
400 m/s
300 m/s
A particle starting from the origin (0, 0) moves in a straight line in the (x, y) plane. Its coordinates at a later time are . The path of the particle makes with the x-axis an angle of
30o
45o
60o
0o
A wheel has angular acceleration of 3.0 rad/s2 and an initial angular speed of 2.00 rad/s. In a time of 2 s it has rotated through an angle (in radian) of
6
10
12
4
Under the influence of a uniform magnetic field a charged particle is moving in a circle of radius R with constant speed v. The time period of the motion
depends on v and not on R
depends on both R and v
is independent of both R and v
depends on R and not on v
A projectile is thrown in the upward direction making an angle of 60° with the horizontal direction with a velocity of 147 ms-1 Then the time after which its inclination with the horizontal is 45°, is
15 s
10.98 s
5.49 s
2.745 s
C.
5.49 s
At the two points of the trajectory during projection, the horizontal component of the velocity is the same.
The horizontal component of velocity at angle 60o = Horizontal component of velocity at 45o
⇒ u cos 60o = v sin 45o
Vertical component of u = u sin 60o
Vertical component of v = v sin 45o
but vy = uy +
t = 5.49 s