Maharashtra Board Class 11 Physics Chapter 3 Motion in a Plane Solution

Maharashtra Board Class 11 Physics Solution Chapter 3 – Motion in a Plane

Balbharati Maharashtra Board Class 11 Physics Solution Chapter 3: Motion in a Plane. Marathi or English Medium Students of Class 11 get here Motion in a Plane full Exercise Solution.

Std

Maharashtra Class 11
Subject

Physics

Chapter

3
Chapter Name

Motion in a Plane


1.) Choose the correct option.

i) An object thrown from a moving bus is on example of

(A) Uniform circular motion

(B) Rectilinear motion

(C) Projectile motion

(D) Motion in one dimension

Answer- C

An object thrown from a moving bus follows projectile motion.

ii) For a particle having a uniform circular motion, which of the following is constant

(A) Speed (B) Acceleration

(C) Velocity (D) Displacement

Answer-A

By definition of uniform circular motion it is the motion in which speed is constant.

iii) The bob of a conical pendulum under goes

(A) Rectilinear motion in horizontal plane

(B) Uniform motion in a horizontal circle

(C) Uniform motion in a vertical circle

(D) Rectilinear motion in vertical circle

Answer- B

The bob of a conical pendulum under goes uniform circular motion in horizontal motion.

iv) For uniform acceleration in rectilinear motion which of the following is not correct?

(A) Velocity-time graph is linear

(B) Acceleration is the slope of velocity time graph

(C) The area under the velocity-time graph equals displacement

(D) Velocity-time graph is nonlinear

Answer-D

For uniform acceleration in rectilinear motion Velocity-time graph is linear.

2.) Answer the following questions.

i) Separate the following in groups of scalar and vectors: velocity, speed and displacement, work done, force, power, energy, acceleration, electric charge, angular velocity.

Answer-

Scalars- speed, work done, energy, power, electric charge.

Vectors- velocity, displacement, force, acceleration, angular velocity.

ii) Define average velocity and instantaneous velocity. When are they same?

Answer-

Average velocity: This is defined as the displacement of the object to thethe time interval taken by object to complete the motion.

iii) Define free fall.

Answer- motion of body under only gravitational force is called free fall.

iv) If the motion of an object is described by x = f (t) write formulae for instantaneous velocity and acceleration.

Answer-

For instantaneous velocity for motion x = f (t) is given by,

It can be seen from this equations that motion along x direction is completely controlled by x components of velocity and acceleration independent on y direction. While motion along y-direction is completely controlled by y-components of velocity and acceleration independent on x-direction. This shows that these two equations are independent of each other.

vi) Derive equations of motion graphically for a particle having uniform acceleration, moving along a straight line.

Answer-

Consider velocity time graph shown in figure

1.) Consider an object traveling along AB at x=0 at t=0. Let initial velocity be u and at time t is v.

As slope of velocity time graph gives acceleration of motion   hence Slope of line AB gives acceleration of motion. Thus,

viii) Show that the path of a projectile is a parabola.

Consider a body is projected with velocity u at an angle of θ as shown in figure. Then,

Horizontal component of ux​= u x´sin (θ).

Vertical component of u, uy​= u cos (θ).

This projectile motion is under gravitational acceleration only and it acts in vertically downward direction only hence

Acceleration on horizontal, ax=0

Acceleration on vertical, ay=−g

Using definition of velocity,

X=ux´x ​t

X=ucosθ´t

t=X/ucosθ………………….(1)

using law of motion for y direction as in y direction acceleration is constant.

Updated: April 25, 2022 — 1:36 pm

Leave a Reply

Your email address will not be published.

six − one =