D. a foot model
btw this is a joke right cuz there ain’t no picture lol
I don't think that 4m has anything to do with the problem.
anyway. here.
A___________________B_______C
where A is the point that the train was released.
B is where the wheel started to stick
C is where it stopped
From A to B, v=2.5m/s, it takes 2s to go A to B so t=2
AB= v*t = 2.5 * 2 = 5m
The train comes to a stop 7.7 m from the point at which it was released so AC=7.7m
then BC= AC-AB = 7.7-5 = 2.7m
now consider BC
v^2=u^2+2as
where u is initial speed, in this case is 2.5m/s
v is final speed, train stop at C so final speed=0, so v=0
a is acceleration
s is displacement, which is BC=2.7m
substitute all the number into equation, we have
0^2 = 2.5^2 + 2*a*2.7
0 = 6.25 + 5.4a
a = -6.25/5.4 = -1.157
so acceleration is -1.157m/(s^2)
Answer:
4. B and D
Explanation:
Two points along a transverse wave (such as the one in the figure) are said to be in phase when:
- the vertical position of the two points is the same
- The oscillation of the wave is going in the same way for both points
Basically, we say that two points are in phase when they are separated by a complete cycle (one complete oscillation) of the wave.
For this wave, we see that point B and C have same displacement, but they are not in phase since in B the oscillation is going down while in C is going up.
Instead, B and D are in phase, because they are separated by one complete cycle: both points have same displacement and the oscillation is going in the same way for both of them.
Answer: D
Explanation: The chemical bonds in the food store energy that is released when we eat it.
