Aperson pushing a horizontal, uniformly loaded, 23.90 kg23.90 kg wheelbarrow of length is attempting to get it over a step of height ℎ=0.=0.370r, where is the wheel's radius. the center of gravity of the wheelbarrow is in the center of the wheelbarrow. what is the horizontal component pxpx of the minimum force p⃗ p→ necessary to push the wheelbarrow over the step? the gravitational acceleration is =9.81 m/s2.

Copper has free electrons per cubic meter. a 71.0-cm length of 12-gauge copper wire that is 2.05 mm in diameter carries 4.85 a of current. (a) how much time does it take for an electron to travel the length of the wire? (b) repeat part (a) for 6-gauge copper wire (diameter 4.12 mm) of the same length that carries the same current. (c) generally speaking, how does changing the diameter of a wire that carries a given amount of current affect the drift velocity of the electrons in the wire?

Scout feels ill one day before school. her mother puts a thermometer in her mouth and the temperature begins to climb to 100°f. what is happening between the cooler thermometer and scout's body? a) scout's body is applying a force to the particles in the thermometer. b) kinetic energy is being transferred from her mouth to the thermometer. c) potential energy is being lost by the thermometer and gained by scout's body. d) the potential energy stored in foods is converted to mechanical energy to raise the mercury in the thermometer.

What is the coefficient of kinetic friction μk between the block and the tabletop?