Một vật treo vào lò xo có khối lượng không đáng kể, chiều dài tự nhiên lo độ cứng k, treo thẳng đứng vào vật m1=100g vào lò xo thì chiều dài của nó là 31 cm. Treo thêm vật m2=100g vào lò xo thì cheièu dài của lò xo là 32 cm. Cho g=10m/s^2 độ cứng của lò xo là:

The ratio of lift to drag l/d for a wing or airfoil is an important aerodynamic parameter, indeed, it is a direct measure of the aerodynamic efficiency of the wing. if a wing is pitched through a range of angle of attack, l/d first increases, then goes through a maximum, and then decreases. consider an infinite wing with an naca 2412 airfoil. estimate the maximum value of l/d. assume that the reynolds number is 9x10^6.

If you wanted to move an electron from the positive to the negative terminal of the battery, how much work w would you need to do on the electron? enter your answer numerically in joules.

The pilot of a helicopter hovers at an altitude of 1200 feet over a park. the angle of depression to the base of a statue is 17 degrees. the angle of depression to the nearest park exit, in line with the statue, is 14 degrees. to the nearest foot, what is the distance from the statue to the exit?