Water is pouring into cubiodal reservior at the 60 litres per minute. If the volumne of reserve is `108 m^3`. Find the number of hours it will take to fill the reservoir.

A geyser heats water flowing at the rate of 3.0 litres per minute from 27^@ C to 77 ^@C . If the geyser operates on a gas burner. What is the rate of consumption of the fuel if its heat of combustion is 4.0×10 4 J/g?

A silver wire of 1 mm diameter has a charge of 90 coulombs flowing in 1 hours and 15 minutes. Silver contains 5.28*10^28 free electrons per cm^3. Find the current in the wire and drift velocity in the electron?

A man in a boat moving away from a light house 100m high takes 2 minutes to change the angle of elevation of the top of light house from 60° to 30°,find the speed of the boat.

Two water taps together can fill a tank in 9(3/8) hours.The tap of larger diameter takes 10 hours less than the smaller one to fill the tank separately.Find the time in which each tap can separately fill the tank.

Two water taps can fill together a tank in 6h 40m.The larger tap takes 3h less than the smaller to fill the tank separately.Find the time in which each tap can separately fill the tank.

The angle of elevation of an aeroplane from a point A on the ground is 60^@ . After a flight' of 30 seconds, the angle of elevation changes to 30^@ . If the plane is flying at a constant height of 3600sqrt3 m , find the speed of the plane in km/hour.

Take two concal flasks and paint one white and other black.Fill both with water. Place the conical flasks in direct sunlight for half an hour to one hour. Touch the conical flasks . Which one is hotter ? You could also measure the temperature of the water in the two conical flasks with a thermometer. Can you think of ways in which this finding could be used in your daily life ?

A bucket made up of a metal sheet is in the form of a frustum of a cone. Its depth is 24 cm and the diameters of the top and bottom are 30 cm and 10 cm respectively. Find the cost of milk which can completely fill the bucket at the rate of ₹ 20 per litre and the cost of metal used, if its cost ₹ 10 per 100 cm^2 (pi = 3.14) .