A hemispherical tank full of water is emptied by a pipe at the rate of `3 4/7` litres per second. How much time will it take to empty half the tank, if it is 3m in diameter? (Take `pi=22/7`)

A river 3 m deep and 40 m wide is flowing at the rate of 2 km per hour. How much water will fall into the sea in a minute?

First order reacton ha specific rate of 10^(-3) s ^(-1). How much time will it take for 10 g of the reactant to reduce to 5 g ?

The refractive index of water is 4//3 .How much time will light take to travel through a water column of length 500 m?

A first order reaction has a rate constant vlaue 10 ^(-3)s ^(-1) . How much time will it take for 10 g of the reactant of reduce to 2. 5 g.

A container, opened from the top and made up of a metal sheet, is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 8cm and 20 cm, respectively. Find the cost of the milk which can completely fill the container, at the rate of ₹ 20 per litre. Also find the cost of metal sheet used to make the container, if it costs ₹8 per 100 cm^2 ( Take pi = 3. 14 )

A container opened from the top is made up of a metal sheet is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 8 cm and 20 cm, respectively. Find the cost of the milk which can completely fill the container, at the rate, of Rs 20 per litre. Also find the cost of metal sheet used to make the container, if it costs Rs 8 per 100 cm^2 . (Take pi = 3.14.)