Bismath has half life of 5 days.A sample originally has a mass of 800 mg.
Find the mass remaining for 30 days.

Calculate the concentration of nitric acid in moles per litre in a sample which has a density. 1.41 g mL^1 and the mass percent of nitric acid in it being 69%.

If the radius of the earth contracts to half of its present radius , then the length of the day will be (if the mass of the earth remaining same)

A body has mass 200 g and volume 100 cm^3 . Find its density and relative density.

A steel piano wire 0.5 m long has a total mass of 0.01 kg and is stretched with a tension of 800 N. The frequency, when it vibrates in its fundamental mode, is

A hydraulic brake system of a car of mass 1000 kg having speed of 50 km//hr . has a cylindrical piston of radius of 0.5 cm. The slave cylinder has a radius of 2.5 cm. if a constant force of 100 N is applied on the brake what distance the car will travel before coming to stop?

A thin uniform rod 2m long has a mass of 0.6 kg. Find its moment of inertia and radius of gyration about an axis perpendicular to its length and passing through: its centre

A thin uniform rod 2m long has a mass of 0.6 kg. Find its moment of inertia and radius of gyration about an axis perpendicular to its length and passing through: one end

A radioactive isotope has a half life of T years : How long will it take the activity to reduce to 1%of its original value?