Answer:
because its not going down a long hill instead its going on a leveled street
can't read it, need larger picture
Answer:
Final speed of boat + man is 1.66 m/s
Explanation:
As we know that there is no friction on the system or there is no external force on this system
So here we can use momentum conservation here

so we have
m = 85 kg
M = 135 kg
v = 4.30 m/s
now we have


Answer: He has only move 0.2 yards
Explanation: When you subtract 18.3 from 18.5 you get 0.2 and that is how much he's moved
Answer:
a) 
b)
º
c) 
Explanation:
From the exercise we know that the collision between Daniel and Rebecca is elastic which means they do not stick together
So, If we analyze the collision we got

To simplify the problem, lets name D for Daniel and R for Rebecca
a) 
Since Daniel's initial velocity is 0



Now, lets analyze the movement in the vertical direction

Since 


Now, we can find the magnitude of Daniel's velocity after de collision

b) To know whats the direction of Daniel's velocity we need to solve the arctan of the angle
º
c) The change in the total kinetic energy is:
ΔK=
ΔK=![\frac{1}{2}[(45kg)(8m/s)^2+(70kg)(7.32m/s)^2-(45kg)(14m/s)^2]=-1094.62J](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%5B%2845kg%29%288m%2Fs%29%5E2%2B%2870kg%29%287.32m%2Fs%29%5E2-%2845kg%29%2814m%2Fs%29%5E2%5D%3D-1094.62J)
That means that the kinetic energy decreases