A swimmer's speed in the direction of flow of river is 16 km h ^-1 . Against the flow of river, the swimmer's speed is 8 km h ^-1 . The swimmer's speed in still water and the velocity of flow of the river respectively are

A particle is thrown vertically upward. Its velocity at half of the height is 10 m /s then the maximum height attained by it is ( g = 10m/s²)

If the velocity is v = 2i + t²j - 9 k , then the magnitude of acceleration at t = 0.5 s is ___

Which one of the following Cartesian

coordinate systems is not followed in

physics?

Identify the unit vector in the following.

Which one of the following physical

quantities cannot be represented by a

scalar?

Two objects of masses m1 and m2 fall

from the heights h1 and h2 respectively.

The ratio of the magnitude of their

momenta when they hit the ground is

If a particle has negative velocity and

negative acceleration, its speed

If an object is dropped from the top of

a building and it reaches the ground at t

= 4 s , then the height of the building is

(ignoring air resistance) (g = 9.8 ms–2)

A ball is projected vertically upwards

with a velocity v. It comes back to ground

in time t. Which v-t graph shows the

motion correctly?

If one object is dropped vertically

downward and another object is thrown

horizontally from the same height, then

the ratio of vertical distance covered by

both objects at any instant t is

A ball is dropped from some height

towards the ground. Which one of

the following represents the correct

motion of the ball?

The dimension of point mass is

A bird flying in the sky is an example of

A unit vector is used to specify

The angle between any two orthogonal unit vectors is

The vector product of any two vectors gives a

The vector product of two vectors will have maximum magnitude when the angle θ is equal to

The ratio of total path length travelled by the particle in a time interval is equal to