Cho 3 điện tích q1 = 2.10-9 C; q2 = 3.10-9 C và q3 = -3.10-9C đặt lần lượt tại 3 đỉnh của một tam giác vuông tại A trong không khí. Cho AB = 3 cm; AC = 4 cm. Tính lực điện do q2 và q3 tác
dụng lên q1.

The slotted link is pinned at o, and as a result of rotation it drives the peg p along the horizontal guide. compute the magnitude of the velocity and acceleration of p along the horizontal guide. compute the magnitudes of the velocity and acceleration of p as a function of θ if θ=(3t) rad, where t is measured in seconds.

When the velocity of an object is doubled, by what factor is its momentum changed? by what factor is its kinetic energy changed? a) the momentum is zero. b) the momentum is not zero. c) difficult to say.

A175 g lump of molten lead at its melting point (327 c) is placed into 55.0 g of water at 20.0 c. the specific heat of lead is 130.j/kg c and the hf of lead is 20,400 j/kg. when the lead and the water have reached equilibrium, what is the temperature of the mixture?