EASY
Earn 100

A person walks 25° north of east for 3.18 km. How far would she have to walk due north and then due east to arrive at the same location?

50% studentsanswered this correctly

Important Questions on Kinematics

EASY

A mosquito is moving with a velocity v=0.5t2i^+3tj^+9k^ m s-1 and accelerating in uniform conditions. What will be the direction of mosquitoes after 2 s ?

EASY
A particle has initial velocity 2i^+3j^ and acceleration 0.3i^+0.2j^. The magnitude of velocity after 10 seconds will be
HARD

Three balls, A, B and C are released and all reach the point X (shown in the figure). Balls A and B are released from two identical structures, one kept on the ground and the other at height h from the ground as shown in the figure. They take time tA and tB respectively to reach X (time starts after they leave the end of the horizontal portion of the structure). The ball C is released from a point at height h vertically above X and reaches X in time tC. Choose the correct statement.

Question Image

EASY

A body of mass 2 kg moves under a force of 2i^+3j^+5k^N It starts from rest and was at the origin initially. After 4 s, its new coordinates are 8,b,20. The value of b is ______.

(Round off to the Nearest Integer)

MEDIUM
The trajectory of a projectile projected from origin is given by the equation y=x-2x25. The initial velocity of the projectile is
EASY

A swimmer can swim with velocity of 12 km/h in still water. Water flowing in a river has velocity 6 km/h. The direction with respect to the direction of flow of river water he should swim in order to reach the point on the other bank just opposite to his starting point is ________°

(Round off to the Nearest Integer) (find the angle in degree)

EASY
A particle moves according to the equation x=asinωt and y=a(1-cosωt). The path of the particle is
HARD
A particle starts from the origin at t=0 s with a velocity of 10j^ m s-1 and move in the x-y plane with a constant acceleration of (8i^+2j^) m s-2. At an instant when the x-coordinate of the particle is 16 m, y-coordinate of the particle is:
HARD

A balloon is moving up in air vertically above a point A on the ground. When it is a height h1, a girl standing at a distance d (point B) from A (see figure) sees it at an angle 45° with respect to the vertical. When the balloon climbs up a further height h2, it is seen at an angle 60° with respect to the vertical if the girl moves further by a distance 2.464 d (point C). Then the height h2 is (given tan30°=0.5774):

Question Image

HARD
Consider a particle moving in the xy plane with velocity v=ai^+bxj^, where i^ and j^ are the unit vectors along x and y axes and a' and b' are constants. If the initial position of the particle is x=y=0, the equation to describe the particle's trajectory in the plane is
MEDIUM
The position of a particle as a function of time is given by rt=Acosωti^+Bsinωtj^ where A and B are two real positive constants with A>B. The orbit of the particle looks like-
EASY
The trajectory of a projectile near the surface of the earth is given as y=2x-9x2. If it were launched at an angle θ0 with speed v0 then g=10 s-2:
MEDIUM
A butterfly is flying with a velocity 42 m s-1 in north-east direction. Wind is slowly blowing at 1 m s-1 from north to south. The resultant displacement of the butterfly in 3 seconds is:
MEDIUM
A ball is thrown horizontally from a height with a certain initial velocity at time t=0 . The ball bounces repeatedly from the ground with the coefficient of restitution less than 1 as shown.
Question Image
Neglect air resistance and taking the upward direction as positive, which figure qualitatively depicts the vertical component of the ball's velocity vy as a function of time (t) ?
EASY
A bird flies at an angle of 60° to the horizontal. Its horizontal component of velocity is 10 m/s. Find its vertical component of velocity in m/s.
MEDIUM
A particle moves over a xy plane with a constant acceleration a=4.0 m s-2i^+4.0 m s-2j^. At the time t=0, the velocity is 4.0 m s-2i^. The speed of the particle when it is displaced by 6.0 m parallel to the x-axis is,
HARD
Two paper screens A and B are separated by 150 m. A bullet pierces A and then B. The hole in B is 15 cm below the hole in A. If the bullet is traveling horizontally at the time of hitting A, then the velocity of the bullet at A is: g=10 m s-2
MEDIUM
A particle moving in a gravity free space along horizontal with a velocity 1 m s-1 is subjected to an acceleration 2 i^+4 j^ m s-2. Then the vertical distance covered by the particle by the time it covers a horizontal distance 6 m is
MEDIUM
A particle starts from the origin at t=0 with an initial velocity of 3.0i^ m s-1 and moves in the x-y plane with a constant acceleration 6.0i^+4.0j^ m s-2. The x- coordinate of the particle at the instant when its y- coordinate is 32 m is D meters. The value of D is:
EASY
The position vector of the particle is rt=acosωti^+asinωtj^, where a and ω are real constants of suitable dimensions. The acceleration is