có một ngôi nhà mái dốc nhà cao 12m mái cao 1,5m rộng 4m người ta bố trí 2 kim thu sét dài bằng nhau tại hai đầu hồi khoảng cách hai kim thu sét là 22m hãy tính chiều cao cảu hai cột thu sét để bảo vệ an toàn cho ngôi nhà

How many molecules are present in 3 mols of silicon dioxide (sio2)?

Suppose you have three polarizing filters, with the second at an angle of 42∘ to the first and the third at an angle of 90∘ to the first. by what perfect will the original intensity of unpolarized light be reduced to after passing through all three filters?

Arocket starts from rest and moves upward from the surface of the earth. for the first 10.0 s of its motion, the vertical acceleration of the rocket is given by ay = 12.80 m/s32t, where the +y-direction is upward. (a) what is the height of the rocket above the surface of the earth at t = 10.0 s? b) what is the speed of the rocket when it is 325 m above the surface of the earth?