Q&A - Ask Doubts and Get Answers

Let the velocity of rain be xi + yj Speed of the rain =  the velocity of man = 3i The relative velocity between man and rain in case one is vertical That is  x=3 since relative velocity has only the vertical component. Case 2 Since the rain is coming at 30 degrees the angle between the relative velocity of rain and man is 150 degree Therefore Therefore
The focal length required is 1/f = 1/v - 1/u here u is taken as infinity and v is -60 cm because the person can see an object up to 60 cm. So a distant object is considered such that the image is formed at 60 cm Therefore 1/f=1/(-60) - 0 f=-60 cm=-0.6 m Power = 1/f = 1/(- 0.6)= -1.667 Diopter.
Everything that we see around has a science involved in it. Some of them are listed below The flow of water from tape, fan, heater, cooking of food, walking, breathing, falling of leaves, moving our body parts, television, mobile phones, vehicles in all the modes of transport, purifiers, machinery in industries, constructions, lighting and thunder, electricity and many other electronic,...
10 % of 250=25 40% of 250 = 100
At first, ball is at height h and energy=mgh After each collision 3/4 energy is lost. Which means 1/4 th of previous value is remaining after each collision, After the first collision energy, E1 = mg (h/4) and ball rises to h/4 Next collision  the energy before the collision is E1 and after = E2= 1/4 E1                         E2= 1/4[1/4 mgh] = (1/4)²  m g h  After nth collision En= (1/4)n  m...
It is an arrangement of four resistances which can be used to measure one of them in terms of rest. Let R is an adjustable resistance, Pand Q are known resistance and S is an unknown resistance. To obtain value of S we will close the keys K1 and K2 and will adjust R to obtain null deflection in the galvanometer. Then the balancing condition of the bridge is   
For a perfectly rigid body deformation is not there, so the strain is zero. Hence youngs modulus (Y=stress /strain) is infinite.
All the three Inductance are in parallel L = 3/3 =1 H  
The 2 ohm resistance at vertex are in series, so the net value is 4 ohm. The 4-ohm resistances are parallel Now all 2 ohms are in series So the net resistance = 6 ohm
Given out of 12, five are red, therefore 12-5=7 are blue. The ratio of red and blue balls is  red/blue = 5/7
Transverse waves - In these types of waves, the particles of the medium vibrate in a direction perpendicular to the direction of propagation of the wave. e.g.wave produced in a long string when one end is fixed.
6+( 5 - 4 + 2 ) =6+(1+2)=6+3=9
To find the ratio first we have to convert to the same units 2l = 2 x 1000 ml = 2000 ml So the ratio is 100/2000 = 1/20
sin 20 = cos 70 since sin x = cos (90-x) Also sec 70=1/cos70 using above results
length=20cm breadth = 40cm area of rectangle= length x breadth=20 x 40 = 800 cm2
five lakh eighty-two thousand and thirty
we have multiplied with 1.6 x 10-19 because it is the value of e and 106 is the value of megavolt to volt.