Có 1 số điện trở R=5 ôm phải dùng ít nhất bao nhiêu điện trở để mắc thành mạch điện có điện trở tương đương bằng 8 ôm

Erosion of the beach is normally a slow process. however, in certain situations, large chunks of shore may wash out to sea. what could cause this to happen?

Wavelength of 125 meters is moving at a speed of 10 m/s. what is it's frequency?

Abatter hits a 0.140-kg baseball that was approaching him at 30 m/s and, as a result, the ball leaves the bat at 40 m/s in the reverse of its original direction. the ball remains in contact with the bat for 2.0 ms. what is the magnitude of the average force exerted by the bat on the ball?