ncert solutions physics class 11th

Get insights from 149 questions on ncert solutions physics class 11th, answered by students, alumni, and experts. You may also ask and answer any question you like about ncert solutions physics class 11th

149
Questions
0
Discussions
0
Active Users
11
Followers

Have a question about ncert solutions physics class 11th? Ask our experts

Ask Your Question

Keep it short & simple. Type complete word. Avoid abusive language.

New answer posted•a year ago

ncert solutions physics class 11th Motion in a Plane

**Q.4.21 A particle starts from the origin at t = 0 s with a velocity of 10.0 ? m/s and moves in the x-y plane with a constant acceleration of (8.0 ? + 2.0 ?) m s^-2.

(a) At what time is the x- coordinates of the particle 16 m? What is the y-coordinate of the particle at that time?

(b)** What is the speed of the particle at the time?

12 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

Ans.4.21:

(a) Velocity , $\overset{?}{v}$ = 10.0 ? m/s

Acceleration, $\overset{?}{a}$ = (8.0 ? + 2.0 ?) m s-2

We know $\overset{?}{a}$ = $\frac{d \overset{?}{v}}{d t}$ = 8.0 ? + 2.0 ?

$\overset{?}{d v}$ = (8.0 ? + 2.0 ?)dt

Integrating both sides we get $\overset{?}{v}$ (t) = 8.0t ? + 2.0t ? + $\overset{?}{u}$ ,

Where, $\overset{?}{u} =$ velocity vector of the particle at t =0

$\overset{?}{v} =$ velocity vector of the particle at time t

But $\overset{?}{v}$ = $\frac{\underset{d r}{?}}{d t}$

$\overset{?}{d r}$ = $\overset{?}{v}$ dt

= (8.0t ? + 2.0t ? + $\overset{?}{u}$ )dt

Integrating both sides with the condition at t = 0, r =0 and at t =t, r = r

$\overset{?}{r} =$ $\overset{?}{u}$ t + ½ $\times$ 8.0 t2 ? + ½ $\times$ 2.0 $\times$ t2 ? = $\overset{?}{u}$ t + 4.0 t2 ? + t2 ?

Substituting the value of $\overset{?}{u}$ , we get

$\overset{?}{r} =$ ( 10.0 ?)t + 4.0 t2 ? + t2 ? . This equation can be expressed as

x ? + y ? = 4.0 t2 ? + ( 10.0t + t2) ?

Since the motion of the particle is confined to the x-y plane, on equating the coefficients of ? and ?, we get

x = 4.0 t2 and y = 10.0t + t2

t = $\sqrt{x / 4}$

(a) When x = 16m, t = 2 s, y = 24m

(b) Velocity of the particle

$\overset{?}{v}$ (t) = 8.0t ? + 2.0t ? + $\overset{?}{u}$

At t = 2 s,

$\overset{?}{v}$ (t) = 8.0 $\times$ 2 ? + 2.0 $\times 2$ ? + 10 $\times$ ? = 16 ? + 14 ?

The magnitude of $\overset{?}{v}$ (t) is given by

$|\overset{?}{v}|$ = ( 162 + 142)1/2 = 21.26 m/s

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Motion in a Plane

4.25 An aircraft is flying at a height of 3400 m above the ground. If the angle subtended at a ground observation point by the aircraft positions 10.0 s apart is 30°, what is the speed of the aircraft?

326 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

4.25

Height of the aircraft from the ground = 3400m

Let A and B be the positions of the aircraft, making an angle of AOB = 30 $°$ . The perpendicular OC and OC is the height of the aircraft. Angles AOC = angle BOC = 15 $°$

In AOC, AC = OC $\tan$
$15 °$ = 3400 $\tan ? 15 °$ = 911.03m

AB = AC + CB = 2AC = 1

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Motion in a Plane

24 Read each statement below carefully and state, with reasons and examples, if it is true or false:

A scalar quantity is one that

(a) Is conserved in a process

(b) Can never take negative values

(c) Must be dimensionless

(d) Does not vary from one point to another in space

(e) Has the same value for observers with different orientations of axes

106 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

4.24

(a) Despite being a scalar quantity, energy is not conserved in elastic collisions. False

(b) Despite being a scalar quantity, the temperature can take negative values. False

(c) The total path length is a scalar quantity. Yet it has the dimension of length. False

(d) A scalar quantity such as

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Motion in a Plane

4.23 For any arbitrary motion in space, which of the following relations are true:

(a) V average = (1/2) (v (t1) + v (t2))

(b) V average = [r (t2) - r (t1)] / (t2 – t1)

(c) V (t) = v (0) + a t

(d) R (t) = r (0) + v (0) t + (1/2) a t²

(e) A average = [v (t2) - v (t1)] / (t2 – t1)

(The ‘average’ stands for average of the quantity over the time interval t1 to t2)

104 Views|Posted a year ago

Asked by Vishal Baghel

Answered by

Vishal Baghel | Contributor-Level 10

a year ago

4.23

(a) For any arbitrary motion of a particle average velocity cannot be expressed by this equation. False

(b) The arbitrary motion of the particle can be represented by this equation, True

(c) For arbitrary motion of the particle, the acceleration may also be non uniform. False

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Dual Nature of Radiation and Matter

What is the significance of de Broglie’s hypothesis in modern physics?

10 Views|Posted a year ago

Asked by Pallavi

Answered by

Chandra Pruthi | Beginner-Level 5

a year ago

Significance of de Broglie's Hypothesis in Modern Physics (NCERT-based answer):

De Broglie's hypothesis is a revolutionary idea which changed the understanding of matter and wave as we know it. This hypothesis introduced the concept that particles of matter, like electrons, and Proton, can behave lik

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Units and Measurements

2.3 A calorie is a unit of heat (energy in transit) and it equals about 4.2 J where 1J = 1 kg m² s^–2. Suppose we employ a system of units in which the unit of mass equals α kg, the unit of length equals β m, the unit of time is γ s. Show that a calorie has a magnitude 4.2 α ^–1 β ^–2 γ ² in terms of the new units.

66 Views|Posted a year ago

Asked by Alok Kumar Singh

Answered by

Alok Kumar Singh | Contributor-Level 10

a year ago

2.3

1 Calorie = 4.2 J = 4.2 kgm²s^-2

Standard formula for conversion

Given unit / New unit = (M1/M2)^x (L1/L2)^y (T1/T2)^z

Formula for energy = M¹L²T^-2

Here x = 1, y = 2, z = -2

In this problem

M1 = 1 kg, L1 = 1 m, T1 = 1 s and

M2 =? kg, L2 =? m, T2 =? s

So 1 Calorie = 4.2 (1/? )¹ (1/? )² (1/? )^-2

= 4.

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Units and Measurements

Q.2.1 Fill in the blanks

5 Views|Posted a year ago

Asked by Alok Kumar Singh

Answered by

Alok Kumar Singh | Contributor-Level 10

a year ago

Ans.2.1

(a) The volume of a cube of side 1 ${c m}^{3}$ is equal to $10^{- 6} m^{3}$

The volume of the cube = 1 cm * 1 cm * 1 cm = 1 cm³

1 cm3 = 1 * 10^-6 m³

(b) The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm is equal to1.25 * 10⁴ (mm)²

The surface area of a solid cylinder = 2? r (r+)h, wh

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Physics Gravitation

8.12 A rocket is fired from the earth towards the sun. At what distance from the earth’s centre is the gravitational force on the rocket zero? Mass of the sun = 2×10³⁰ kg, mass of the earth = 6×10²⁴ kg. Neglect the effect of other planets etc. (orbital radius = 1.5 × 10¹¹ m).

8 Views|Posted a year ago

Asked by Pallavi Pathak

Answered by

Pallavi Pathak | Contributor-Level 10

a year ago

8.12

Mass of the Sun, $M_{s}$ = $2 \times 10^{30}$ kg, Mass of the Earth, $M_{e}$ = $6 \times 10^{24}$ kg

Orbital radius, r = $1.5 \times 10^{11}$ m

Let the mass of the rocket be, m

Let x be the distance from the centre of the Earth where the gravitational force acting on satellite P becomes zero.

From Newton’s law of grav

Upvote

New answer posted•a year ago

ncert solutions physics class 11th NCERT Physics 11th

Q.8.1 Answer the following:

(a) You can shield a charge from electrical forces by putting it inside a hollow conductor. Can you shield a body from the gravitational influence of nearby matter by putting it inside a hollow sphere or by some other means?

(b) An astronaut inside a small space ship orbiting around the earth cannot detect gravity. If the space station orbiting around the earth has a large size, can he hope to detect gravity?

(c) If you compare the gravitational force on the earth due to the sun to that due to the moon, you would find that the Sun’s pull is greater than the moon’s pull

(You can check this yourself using the data available in the succeeding exercises). However, the tidal effect of the moon’s pull is greater than the tidal effect of sun. Why?

4 Views|Posted a year ago

Asked by Santosh

Answered by

Pallavi Pathak | Contributor-Level 10

a year ago

Ans.8.1

(a) No. Unlike electrical forces, gravitational force is independent of the status of the objects.

(b) Yes, the size of the space station is large enough and the astronaut will detect the change in Earth's gravity.

(c) Tidal effect depends inversely upon the cube of the distance

Upvote

New answer posted•a year ago

ncert solutions physics class 11th Motion

What is the difference between periodic and oscillatory motion?

7 Views|Posted a year ago

Asked by Pallavi Pathak

Answered by

Pallavi Pathak | Contributor-Level 10

a year ago

An example of the periodic motion is Earth's revolution. In this, the motion repeats itself after regular intervals of time. In oscillatory motion, the object moves back and forth about a mean position like a vibrating spring or pendulum. It is a type of periodic motion. Although, oscillatory motion

Upvote

ncert solutions physics class 11th

Questions

Discussions

Active Users

Followers