Answer plzzz dan does 188.0 j of work raking leaves. if the rake does 128.0 j of work, what is the efficiency of the rake? a. 68.1 percent b. 147.0 percent c. 60.0 percent d. 316.0 percent a force of 29.0 n is used to lift a baby through a distance of 0.500 m. how much work is done on the baby? a. 29.5 j b. 58.0 j c. 14.5 j d. 28.5 j

In which of the following would the particles move most rapidly? a. ice at -20 °c b. water at 20 °c c. steam at 110 °c d. boiling water e. ice at 0 °c

At 20∘c, the hole in an aluminum ring is 2.800 cm in diameter. you need to slip this ring over a steel shaft that has a room-temperature diameter of 2.804 cm . 1. to what common temperature should the ring and the shaft be heated so that the ring will just fit onto the shaft? coefficients of linear thermal expansion of steel and aluminum are 12×10−6 k−1 and23×10−6 k−1 respectively.

Point charges q1=+2.00μc and q2=−2.00μc are placed at adjacent corners of a square for which the length of each side is 1.50 cm . point a is at the center of the square, and point b is at the empty corner closest to q2. take the electric potential to be zero at a distance far from both charges. part a what is the electric potential at point a due to q1 and q2? express your answer with the appropriate units.