Doubtly
@Doubtly · Joined Feb 2021
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- b. Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in .... Alkaline earth metals have valency 2. This means that their position in the modern periodic table is in Group 2 1
- a. The number of electrons in the outermost shell of alkali metals is...... (i) 1 (ii) 2 (iii) 3 (iv) 7 The number of electrons in the outermost shell of alkali metals is 1 1
- how to know the answer is relavant ? You can find relavant answer Conditions :: 1) Check whether answer is selected as best or not ? This symbol means best answer , check if the... 1
- 1. Rearrange the columns 2 and 3 so as to match with the column 1. Ans. (i – c – 5 ) , (ii – d – 3) , (iii – e – 6 ) , (iv – f – 1) , (v – b – 4), (vi - a – 2). Column 1 Column 2 Column 3 i. Triad c. Average... 1
- Take weights of five of your friends. Find out what their weights will be on the moon and the Mars. Take weights of five of your friend find out what their weights will be on the moon and the mars Let the weights of my friends a,b,c,d,e be... 3
- A cylindrical vessel containing a liquid is rotated about its axis so that the liquid rises at its sides as shown in the figure. The radius of vessel is Correct option is A) 25ω²/2g Explaination:: Applying pressure equation from A to B p_o+ρ.Rω²/2.R-ρ gh= p_o ρ.R²ω²/2=ρ gh h=R²ω²/2g=5²ω²/2g=2... 1
- If intensity after passing through a polaroid is 100 Lumen. Now this same polaroid is rotated by 30° about it's axis then The correct answer is option 2) 100 lumens I_(p_1)=I_p2=100 Lumens 1
- std 10th maharashtra board science part 1 gravitation notes Download pdf for offline study 1. study the entries in the following table and rewrite them putting the corrected items in a single row :gra... 2
- g. The mass of the earth is 6 x 1024 kg. The distance between the earth and the Sun is 1.5x 1011 m. the mass of the earth, m = 6 × 10²⁴ kg Assume the mass of the sun is M distance between earth and sun , r = 1.5 × 10¹¹ m force between sun a... 1
- f. The masses of the earth and moon are 6 x 1024 kg and 7.4x1022kg, respectively. The distance between them is 3.84 x 105 km. Given : Mass of the Earth(m₁) = 6 × 10²⁴ kg. Mass of the Moon(m₂) = 7.4 × 10²² kg. Distance between the Earth and the Moon(d) = 3.84 × 10⁵ k... 1
- e. A ball falls off a table and reaches the ground in 1 s. Assuming g = 10 m/s2 , calculate its speed Given: t=2s , g=10 m/s² , u=0 , a=g , s=? , v=? Solution : s=ut+1/2 gt² = 0× 1+ 1/2 (10)(1)² = 1/2 (10) s= 5m v=u+gt =0+10*1 v=10 m/s The an... 1
- d. An object thrown vertically upwards reaches a height of 500 m. What was its initial velocity? the final velocity is zero. We know the position is 500 and acceleration is 10 Let the initial velocity = u final velocity = v v= 0 m/s s =... 1
- c. The mass and weight of an object on earth are 5 kg and 49 N respectively. What will be their values on the moon? Mass of the substance remains constant. It is the multiplication of density and volume that will remain unchanged in the whole universe. So... 2
- b. The radius of planet A is half the radius of planet B. If the mass of A is MA, what must be g= GMover R² ⇒ M=gR²/G Acording to the given data , gB/gA=1/2 and tfracR_BR_A=2 ⇒ M_B/M_A=g_B/g_A( R_B/R_A)² ⇒ M_B/M_A=1/22² ⇒ M_B=2M_A Vide... 1
- a. An object takes 5 s to reach the ground from a height of 5 m on a planet. What is the value of g on the planet? Given : Time= 5s , Height=5m To find : Gravitational acceleration Formula: S=ut+1/2gt² steps: by formula 5=0× t+1/2g(5)² 5=1/2g×25 therefore... 1
- 4. Let the period of revolution of a planet at a distance R from a star be T. Prove that if it was at a distance of 2R from the star, Thus, when the period of revolution of the planet at a distance R from a star is T, then from kepler's third law of planetry motion, we have... 1
- 3. Explain why the value of g is zero at the centre of the earth. Acceleration due to the earth's gravity is zero at the centre of the Earth because at that point the mass of the earth is equally distribute... 1
- e. If the value of g suddenly becomes twice its value, it will become two times more difficult to pull a heavy object along the floor. Why? Let the mass of the heavy object be m. Thus, the weight of the object or the pull of the floor on the object is W=mg Now, if g becomes twice... 2