Test: Motion in a Plane (NCERT) - NEET MCQ

 Displacement vector from A to B is given by

Resolving displacement 30√2 m south-west into two rectangular components, we get
Displacement in south

∴ Effective displacement due to 30 m north and 30 m south is zero.
Also effective displacement due to 30 m east and 30 m west in zero.

Displacement of each girl = 
Magnitude of displacement for each girl
For girl C, displacement = actual length of path.

(i) The work done on a body moving in a circular path is also zero. This is because, when a body moves in a circular path, then the centripetal force acts along the radius of the circle, and it is at right angles to the motion of the body.

(ii) Thus, the work done in the case of moon moving round the earth is also zero.

In a uniform circular motion, the acceleration is directed towards the centre while velocity is acting tangentially.

v = rω
= 0.5 x 70
= 35 m/s

The velocity with which a bullet or shell leaves the muzzle of a gun.
We  know that in projection of the particle for maximum range, θ = 45°
Now maximum range
R = (µ²sin2θ)/g
R = (µ²sin90º)/g (sin90º = 1)
µ = √Rg .........(1)
R_max = 16km = 16 x 10³ m
g = 10m/s²
From equation (1):
µ = √(16 x 10³ x 10)
µ = 400 m/s

When velocity of projection of a body is made n times, and its time of flight becomes n times and range becomes  n² times.
so Assertion is correct but Reason is incorrect