A child jumps from a moving sled with a speed of 2.5 m/s and in the direction opposite the sled’s motion. The sled continues to move in the forward direction, but with a new speed of 6.3 m/s. If the child has a mass of 38 kg and the sled has a mass 63 kg, what is the initial velocity of the sled?

Two red blood cells each have a mass of 9.0 multiply. gif 10-14 kg and carry a negative charge spread uniformly over their surfaces. the repulsion arising from the excess charge prevents the cells from clumping together. one cell carries −2.50 pc of charge and the other −3.10 pc, and each cell can be modeled as a sphere 7.5 μm in diameter. (a) what speed would they need when very far away from each other to get close enough to just touch? assume that there is no viscous drag from any of the surrounding liquid. answer is: 321 m/s how do i find this (b) what is the maximum acceleration of the cells in part (a)? answer is: 1.38e+10 m/s2 how did they find this answer

Science and technology are interdependent. advances in one lead to advances in the other. give an example of this phenomenon.

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is