If the angular distance between two stars is 3°, which of these statements must be true? Select all that apply.
A. The parallax of each star is known.
B. The linear distance between the stars is known.
C. The linear distance of each star to Earth is known.
D. The angular separation between the stars is known.

Asmall electric heater, immersed in 80g of water in a calorimeter of 40j/k raises the temperature from 10.5 degree celsius to 25 degree celsius in 12 minutes. using the same apparatus with 50g of oil instead of water, it is found that the temperature of oil rises from 7 degree celsius to 27 degree celsius in 10 minutes. find specific heat capacity of the oil.