Dòng điện không đổi có cường độ 16A đi qua dây kim loại có đường kính tiết diện 2,0mm mật độ electron tự do trong đoạn dây 10^22 cm^3. Tính tốc độ chuyển độbg định hướng của các electron tự do

Agymnast dismounts off the uneven bars in a tuck position with a radius of 0.3m (assume she is a solid sphere) and an angular velocity of 2rev/s. during the dismount she stretches out into the straight position, with a length of 1.5m, (assume she is a uniform rod through the center) for her landing. the gymnast has a mass of 50kg. what is her angular velocity in the straight position?

Oxygen and hydrogen gas are at the same temperature t. what is the ratio of kinetic energies of oxygen molecule and hydrogen molecule if oxygen is 16 times heavier than hydrogen.

If 2 moles of co_2 at 2l and 500k are expanded reversibly to 20l, more work can be obtained from an adiabatic process than from an isothermal process. is the above statement true or false?