1 Fig. 4.1 shows a small wind-turbine used to generate electricity. The wind-turbine drives an electric generator.
The wind blows with a velocity of 7.0m/s at right angles to the plane of the turbine. The mass of air passing per second through the turbine is 6.7 kg.
(a) (1) Calculate the kinetic energy of the air blown through the turbine per second.
(ii) Only 8% of this energy is converted to electrical energy. Calculate the power output of the electric generator.​

Abatter hits the baseball a with an initial velocity of v0 = 110 ft/sec directly toward fielder b at an angle of 23° to the horizontal; the initial position of the ball is 2.2 ft above ground level. fielder b requires 0.44 sec to judge where the ball should be caught and begins moving to that position with constant speed. because of great experience, fielder b chooses his running speed so that he arrives at the “catch position” simultaneously with the baseball. the catch position is the field location at which the ball altitude is 8.4 ft. determine the velocity of the ball relative to the fielder at the instant the catch is made.

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Convection occurs when thermal energy is transferred by the movement of