Bắn đồng thời một proton và một electron vào từ trường đều theo phương vuông góc với các đường sức từ với cùng một vận tốc đầu. Khi proton quay được 1 vòng thì electron quay được bao nhiêu vòng? Cho mp = 1,67.10– 27 kg, me = 9,10.10 – 31kg.

Boxing gloves are padded to lessen the force of a blow. (a) calculate the force exerted by a boxing glove on an opponent’s face, if the glove and face compress 7.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. (b) calculate the force exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (c) discuss the magnitude of the force with glove on. does it seem high enough to cause damage even though it is lower than the force with no glove?

If y gets smaller as x gets bigger and y have an relationship?

Suppose that three astronomical objects, 1, 2, and 3 are observed to lie on a line, and the distance from object 1 to object 3 is d. object 1 has four times the mass of object 3, and seven times the mass of object 2. find the distance between objects 1 and 2 for which the net force on object 2 is zero.