compute the work done when compressing 4 kg of dry air isothermally to one-tenth of its original volume at 20 c

An astronomer at the equator measures the doppler shift of sunlight at sunset. from this, she calculates that earth’s tangential velocity at the equator is 465 m/s. the centripetal acceleration at the equator is 3.41  10 2 m/s 2 . use this data to calculate earth’s radius.

Which type of electromagnetic waves are dangerous enough to be used to kill cancerous cells? (a)gamma rays (b)visible light (c)infrared light (d)microwaves

Heena wants to measure the volume of a ball that is 24 cm across. how should she set up her equation?