# Amena.S

1. ## Physics

Over a time interval of 1.98 years, the velocity of a planet orbiting a distant star reverses direction, changing from +21.9 km/s to -17.2 km/s. Find (a) the total change in the planet's velocity (in m/s) and (b) its average acceleration (in m/s2) during
2. ## physics

A 20 kg sphere is at the origin. A 10 kg sphere is at (x,y) = (-30cm,0cm) and a 30 kg sphere is at (0cm,40cm). Calculate the gravitational force on the 10 kg sphere, resulting from the other two spheres. Please help! Thanks
3. ## General Chemistry

NH4+ + NO2- = N2 + 2H2O A reaction is run, and the liberated N2 gas is collected in a previously evacuated 500 mL container. After the reaction has gone on for 750 seconds, the pressure of N2 in the 500 mL container is 2.77 x 10^-2 atm , and the
4. ## General Chemistry

Liquid Freon (CCl2F2) is used as a refrigerant. It is circulated inside the cooling coils of older refrigerators or freezers. As it evaporates, it absorbs heat. How much heat can be removed by 2.00 kg of Freon as it evaporates inside the coils of a
5. ## General Chemistry

A 1.50 rubber balloon balloon is filled with carbon dioxide gas at a temperature of 0.00 degrees celsius and a pressure at 1.00 atm. The density of carbon dioxide under these conditions are 1.98 g/L. At 50.0 degrees celsius, the balloon has a volume of