Electrochemistry lecture-2 for Bihar board (crash course)

The inventor of the chess board suggested a reward of one grain of wheat for the first square, 2 grains for the second, 4 grains for the third and so on, doubling the number of the grains for subsequent squares. How many grains would have to be given to inventor? (There are 64 square in the chess board).

The inventor of the chess board suggested a reward of one grain of wheat for the first square, 2 grains for the second, 4 grains for the third and so on, doubling the amount of the grains for subsequent squares. How many grains would have to be given to the inventor? (There are 64 squares in the chess board).

Two painters are working from a wooden hoard 5 m long suspended from the top of a building by two ropes attached to the ends of the plank. Either rope can withstand a maximum tension of 1040 N . Painter A of mass 80 kg is working at a distance of 1 m from one end. Painter B of mass 60 kg is working at a distance of x in from the centre of mass of the board on the other side. Take mass of the board as 20 kg and g = 10ms^(-2) . The range of x so that both the painters can work safely is

A ship is moving at a constant speed of 10 km//hr in the direction of the unit vector hat(i) . Initially. Its position vector, relative to a fixed origin is 10(-hat(i)+hat(j)) where hat(i) & hat(j) are perpendicular vectors of length 1 km. Find its position vector relative to the origin at time t hours later. A second ship is moving with constant speed u km//hr parallele to the vector hat(i)+2hat(j) and is initially at the origin (i) If u=10 sqrt(5) km//h . Find the minimum distance between the ships and the corresponding value of t (ii) Find the value of u for which the shipd are on a collision course and determine the value of t at which the collision would occur if no avoiding action were taken.

In how many ways can a student choose a programme of 5 courses if 9 courses are available and 2 specific courses are compulsory for every student?

In how many ways can a student choose a programme of 5 courses if 9 courses are available and 2 specific courses are compulsory for every student?

In how many ways can a student choose a programme of 5 courses if 9 courses are available and 2 specific courses are compulsory for every student?

A square dart board is placed in the first quadrant from x=0 to x=6 and y=0 to y=6 . A triangular region on the dart board is enclosed by the lines y=2,x=6 and y=xdot Find the probability that a dart that randomly hits the dart board will land in the triangular region formed by the three lines.

a. Estimate the force with which a karate master strikes a board, assuming that hand's speed at the moment of impact is 10.0ms^(-1) , decreasing to 1.00ms^(-1) during a 0.002 s time interval of contact between the hand and the board. The mass of his hand and arm is 1.00 kg . b Estimate the shear, assuming this force it exerted on a 1.00 cm thick pine board that is 10.0 cm wide. c. If we maximum shear stress a pine board can support before breaking is 3.60xx10^(6)N//m^(2) , will the board break?

A ball after having fallen from rest under the influence of gravity for 6 s crashes through a horizontal glass plate, thereby losing two-third of its velocity. It then reaches the ground in 2 s, find the height of the plate above the ground.