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
Each time you exhale, you are releasing carbon dioxide gas (CO2) into the atmosphere. Animals and plants get rid ofcarbon dioxide gas through a process called respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned.
Answer:
128379.69 J
Explanation:
Potential energy: This can be defined as the energy of a body to to position in the gravitational field. The S.I unit of potential energy is Joules (J).
The expression for potential energy is given as,
ΔEp = mgΔH
ΔEp = mg(H₂-H₁)..................... Equation 1
Where ΔEp =change in Potential Energy, m = mass of the man, g = acceleration due to gravity, H₂ = Height of the 37th floor, H₁ = height of the first floor
Given:m = 91.2 kg, g = 9.8 m/s², H₁ = 3.99 m, H₂ = 3.99×37 = 147.63 m.
Substitute into equation 1
ΔEp = 91.2(9.8)(147.63-3.99)
ΔEp = 893.76(143.64)
ΔEp = 128379.69 J.
<h3>
Answer: 28 m/s</h3>
Work Shown:
- Vi = starting or initial velocity = 10 m/s
- Vf = unknown final velocity
- a = acceleration = 3 m/s^2
- t = duration of time = 6 seconds
Use those values in the following kinematic equation
Vf = Vi + a*t
Vf = 10 + 3*6
Vf = 10 + 18
Vf = 28
The final velocity is 28 m/s
