Which of the following scenarios represent a negative displacement? (Assume positive position is measured upward)
-A cat stands on a tree limb
-A cat jumps from the ground onto a tree branch
-A cat jumps from a lower tree branch to a higher tree branch
-A cat jumps from a tree branch to the ground

Given the position vector of the particle r(t)=(t+1)i+(t^2−1)j+2t k, find the particle's velocity and acceleration vectors at t=1

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 .

James joule carefully measured the difference in temperature of the water at the top and bottom of a waterfall. why did he expect a difference