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The scalar product of two vector A and B is

Posted by Vishakha Yadav 3 years ago

1 answers

Vasudha Vasudha 2 years, 11 months ago

The scalar product of a and b is: a · b = |a||b| cosθ We can remember this formula as: “The modulus of the first vector, multiplied by the modulus of the second vector, multiplied by the cosine of the angle between them

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Is acceleration due to gravity always negative?

Posted by Pooja Tarai 3 years ago

CBSE > Class 11 > Physics

4 answers

Naman Patel 2 years, 11 months ago

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Anjan Karthi 2 years, 11 months ago

No, it depends upon how we apply Sign conventions in the situation. If we take downwards as -ve and upwards as +ve, then g becomes -ve and when we take downwards as +ve and upwards as -ve, then g would be positive.

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Sneha Sneha 2 years, 11 months ago

Yes it would be because acceleration due Gravity is always downwards in -ve y axis

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Vasudha Vasudha 2 years, 11 months ago

Towards the center of the Earth, the gravity is defined to the be negative. At all points on the trajectory of a projectile, the gravitational acceleration points in the same direction, which is downwards toward the center of the Earth. So, the sign for the gravitational acceleration is always negative.

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Mcq questions

Posted by Kiran Kumari 3 years ago

CBSE > Class 11 > Physics

1 answers

Shivani Choudhary 3 years ago

Give the common name of periplanata American

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Which is odd one ? (a) displacement (b) potential energy (c)torqe (d) momentum

Posted by Nidhi Sharma 3 years ago

CBSE > Class 11 > Physics

5 answers

Srishti Soumya 3 years ago

Potential energy

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Anupriya Maurya 3 years ago

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Nidhi Sharma 3 years ago

Please tell the exact one!!

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Jyoti Sharma 3 years ago

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Mansi Gupta 3 years ago

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When electron flows through a wire and a circular loop is held above, what is the direction of the induced current in the circular loop?

Posted by Ganesan Sankar 3 years ago

CBSE > Class 11 > Physics

1 answers

Jyoti Sharma 3 years ago

The current will change direction as the electron passes through the circular loop

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Two vectors, both equal in magnitude, have their resultant equal in magnitude of the either. Find the angle between the two vectors.

Posted by Cilestina Lepcha 3 years ago

CBSE > Class 11 > Physics

1 answers

Vasudha Vasudha 2 years, 11 months ago

|A+B−→−−−|=|A→|2+|B→|2+2|A→||B→|cosθ−−−−−−−−−−−−−−−−−−−−−−−√ Complete answer: Let the two vectors be |A→| and |B→|. θ be the angle between both the vectors. Both the vectors have the same magnitude. ∴|A→|=|A→| …(1) Let the resultant have magnitude equal to vector A. Thus, the resultant is given by, |A→|=|B→|=|A+B−→−−−| …(2) The magnitude of resultant of two vectors is given by, |A+B−→−−−|=|A→|2+|B→|2+2|A→||B→|cosθ−−−−−−−−−−−−−−−−−−−−−−−√ …(3) From the equation. (2) and equation. (3) we get, |A→|=|A→|2+|B→|2+2|A→||B→|cosθ−−−−−−−−−−−−−−−−−−−−−−−√ Squaring both the sides we get, ⇒|A→|2=|A→|2+|B→|2+2|A→||B→|cosθ Substituting equation. (1) in above equation we get, |A→|2=|A→|2+|A→|2+2|A→||A→|cosθ ⇒|A→|2=2|A→|2+2|A→||A→|cosθ ⇒−|A→|2=2|A→||A→|cosθ ⇒cosθ=−12 ⇒θ=cos−1(12) ⇒θ=120° Hence, the angle between the two vectors is 120°.

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A tank 10 m high is half filled with water and then filled with oil of density 750kg m3.what is the pressure at the bottom of tank due to this liquid?

Posted by Muskan Johal 3 years ago

CBSE > Class 11 > Physics

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A gun fire of bullet of mass 40gram with speed of 1200m/s .which required a force of 144 newton. Calculate the number of bullet fire in 1 second

Posted by Ansh Saurav Kashyap 3 years ago

CBSE > Class 11 > Physics

1 answers

Anjan Karthi 2 years, 11 months ago

F = n × ma = n × mv/t. Therefore, n = F/mv = 144 × 1000 / 1200 × 40 = 3//

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A stone weighs 100N on the surface of Earth. Find the ratio of its weight at a height of half the radius of Earth to the depth of half the radius of Earth.

Posted by Bholu Rahar 3 years ago

CBSE > Class 11 > Physics

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Find the angular velocity of second hand, minutes hand,hour hand of a clock.Also find the linear velocity of each needle if the length of the needle 15cm,10cm,5cm respectively

Posted by Mahak Maddhhesiya 3 years ago

CBSE > Class 11 > Physics

0 answers

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check the correctness of relation v=sqrt2GM/R

Posted by Dimpal Kumari Mali B 3 years ago

CBSE > Class 11 > Physics

1 answers

Anjan Karthi 2 years, 11 months ago

LHS →v = [LT^-1]. RHS → √GM/R = { [M^-1L^3T^-2] [M] / [L] }^1/2 = { [L^2T^-2] }^1/2 = [LT^-1]. Therefore, LHS = RHS.

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Scope of excitement of physics

Posted by Arman Verma 3 years ago

CBSE > Class 11 > Physics

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A Satellite is at a height of400m Find Vo and total energy

Posted by Soniya Rana 3 years ago

CBSE > Class 11 > Physics

1 answers

Anjan Karthi 3 years ago

Vo = √GM/R+h = √6.67 × 10^-11 × 6 × 10^24 / 6.4 × 10^6 + 400 = 40.02 × 10^13 / 6400 × 10^3 + 400 = 40.02 × 10^13 / 400 (16001) = 40.02 × 10^13 / 6400400 = 40.02 × 10^13 / 6.4004 × 10^6 = 6.25 × 10^7 m/s. //

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. A Satellite is at a height of foorem. Find Vo and total energy

Posted by Soniya Rana 3 years ago

CBSE > Class 11 > Physics

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Determine the kinetic energy a 5000kg space craft must have in order to escape the Earth's gravitational field. Mass of the Earth =6.0×1024 kg radius of the Earth=6.4=106m;g=6.67×10 -11 nm^kg-^

Posted by Yash Babre 3 years ago

CBSE > Class 11 > Physics

1 answers

Anjan Karthi 3 years ago

KE required = 1/2 × m × Ve^2 = 5000 × 2 × 6.67 × 10^-11 × 6 × 10^24 / 6.4 × 10^6 × 2 = 400.2 × 10^16 / 12.8 × 10^6 = 31.265 × 10^10 J//

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Physics mcqs

Posted by Manisha Pathak 3 years ago

CBSE > Class 11 > Physics

0 answers

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Physics mcqs

Posted by Manisha Pathak 3 years ago

CBSE > Class 11 > Physics

1 answers

Ankul Prajapati 3 years ago

Light year

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How to find significant figures

Posted by Saloni Taank 3 years ago

CBSE > Class 11 > Physics

1 answers

Vijay Vishwakarma 3 years ago

All non zero no. Are SF

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The sign of work done by a force

Posted by Tenzin Choney 3 years ago

CBSE > Class 11 > Physics

0 answers

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A man can do work of 600J in 2 min then power is

Posted by Palak Singh 3 years ago

CBSE > Class 11 > Physics

3 answers

Aditya Dubey 3 years ago

5 waat

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Ragini Gupta 3 years ago

Work = 600j Time = 2 min = 2×60= 120 sec Power = work/time = 600/120 = 5 j/s = 5 watt

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Yogiraj Vidhyarthi 3 years ago

5watt

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A wire length 10m and diameter 2mm hanging vertically is loaded by 6.28 kg mass. If it enlongates by 1mm

Posted by Mohit Yadav 3 years ago

CBSE > Class 11 > Physics

1 answers

?Shreya.Kamalakar✔️ Naik 3 years ago

kyxs

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Find the conversion factor between the SI and CGS unit of work using dimensional analysis

Posted by Pranjali Thakre 3 years ago

CBSE > Class 11 > Physics

1 answers

Anjan Karthi 3 years ago

1 joules = 10^7 ergs.

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Object of weight w is resting on a inclined plane at an angle theta to the horizontal the coefficient of static friction is new find the horizontal force needed to just push the object of the incline plane

Posted by Nivedita Corner 3 years ago

CBSE > Class 11 > Physics

1 answers

Anjan Karthi 3 years ago

Horizontal force = new W cosθ - W sinθ

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A woman pushes a box of mass 20 kg on a horizontal surface with a force of F the coefficient of static and kinetic friction are 0.6 and 0.5 what must F be in order that she can make the box start to slide if we maintain the same force once the block start to slide what will be its acceleration

Posted by Nivedita Corner 3 years ago

CBSE > Class 11 > Physics

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A 3 kg box rest on a horizontal table. The coefficient of static and kinetic friction between the box and the table are 0.6 and 0.5 the box is pulled by a string at an angle of 30 degree find the frictional force and the acceleration of the box if tension in the string is 10 Newton

Posted by Nivedita Corner 3 years ago

CBSE > Class 11 > Physics

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Cell magic (changing light energy to electrical energy) project file

Posted by Aman Yadav 3 years ago

CBSE > Class 11 > Physics

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A motorcycle stunt rider rides off the edge of cliff. Just at the edge his velocity is horizontal with magnitude 9m/s . Find the magnitude of the motorcycles position vector after 0.50s it leaves the edge of the cliff

Posted by Shrishti Mishra 3 years ago

CBSE > Class 11 > Physics

1 answers

Ankit Kumar Sain 3 years ago

Solution verified Verified by Toppr At t=0..50s the x−and y- coordinates are x=v 0x t =(9.0ms −1 )(0.50s)=4.5m y=− 2 1 gt 2 =− 2 1 (10ms −2 )(0.50s) 2 =− 4 5 m the negative value of y shows that this time the motorcycles is below its starting point. The motorcycle's distance from the origin at this time. r= x 2 +y 2 = ( 2 9 ) 2 +( 4 5 ) 2 = 4 349 m The components of velocity at this time are v x =v 0x =9.0ms −1 v y =−gt=(−10ms −2 )(0.50s)=−5ms −1 The speed (magnitude of the velocity ) at this time is v= v x 2 +v y 2 = (9.0ms −1 ) 2 +(−5ms −1) 2 = 106 ms −1

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A man can swim with speed of 4km/hr in still water. How long does he take to cross a river 1km wide if the river flows steadily at 3km/hr and he makes his strokes normal to the river current?

Posted by Nikita Jain 3 years ago

CBSE > Class 11 > Physics

1 answers

Ankit Kumar Sain 3 years ago

Solution verified Verified by Toppr Since he makes his strokes normal to the river current, the movement of the river will have no effect on the time of crossing the bank. The time will be, T= Speed Distance = 4 1 hr=0.25hr=15min. In the same time, he will go down by Distance=Speed x time=3km/hr x 0.25hr=0.75km=750m

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A ball is kicked at an angle of 35° with the ground. a.. What should be the initial velocity of the ball so that it hits a target that is 30metre away at a height of 1.8meter ? b... What is the time for the ball to reach the target?

Posted by Rahul Parul 3 years ago

CBSE > Class 11 > Physics

1 answers

Ankit Kumar Sain 3 years ago

Answer: hola mate here is ur answer a) x = V0 cos(35°) t 30 = V0 cos(35°) t t = 30 / V0 cos(35°) 1.8 = -(1/2) 9.8 (30 / V0 cos(35°))2 + V0 sin(35°)(30 / V0cos(35°)) V0 cos(35°) = 30 √ [ 9.8 / 2(30 tan(35°)-1.8) ] V0 = 18.3 m/s b) t = x / V0 cos(35°) = 2.0 s tq♥️

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Notes of chapter 2,3,4

Posted by Ankit Kumar Sain 3 years ago

CBSE > Class 11 > Physics