Which of these best dscribes earth's mantle? a. most dense layer, consists of the outer and inner parts b. thinnest under the oceans and thickest under continents c. middle layer, density increases with depth as pressure increases d. least dense layer overall, consists of two layers of different thickness

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .