Answer:
600 J
Explanation:
The formula to find the kinetic energy of an object is
- m = mass in kg
- V = velocity in m/s
- KE is measured in Joules just as all other forms of energy.
Now, let's plug in the variables we're given and simplify.
Thus, the answer is 600 Joules.
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
Answer:
4611.58 ft/s²
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration due to gravity = 32.174 ft/s²
Equation of motion


Magnitude of acceleration while stopping is 4611.58 ft/s²
Answer:
200 W
Explanation:
The power is given by the ratio between the amount of work done and the time taken to perform the work:

where in this problem we have
W = 2600 J is the work done
t = 13 s is the time taken to do the work
Substituting the numbers into the equation, we find
