Observe that the object below moves in the negative direction with a changing velocity. An object which moves in the negative direction has a negative velocity. If the object is slowing down then its acceleration vector is directed in the opposite direction as its motion (in this case, a positive acceleration). The dot diagram shows that each consecutive dot is not the same distance apart (i.e., a changing velocity). The position-time graph shows that the slope is changing (meaning a changing velocity) and negative (meaning a negative velocity). The velocity-time graph shows a line with a positive (upward) slope (meaning that there is a positive acceleration); the line is located in the negative region of the graph (corresponding to a negative velocity). The acceleration-time graph shows a horizontal line in the positive region of the graph (meaning a positive acceleration).
I don't know how I can show you the figure
Answer:
a

b

Explanation:
From the question we are told that
Their distance apart is 
The wavelength of each source wave 
Let the distance from source A where the construct interference occurred be z
Generally the path difference for constructive interference is

Now given that we are considering just the straight line (i.e points along the line connecting the two sources ) then the order of the maxima m = 0
so

=> 
=> 
Generally the path difference for destructive interference is

=> 
=> 
substituting values

=> 
So


and

=> 
=> 
To calculate the velocity of the sound wave, we use this formula:
V = 331 + [0.6*T],
Where V is the velocity and T represents temperature.
When the temperature is 36 degree Celsius, we have
V = 331 + [0.6 * 36]
V = 331 + 21.6 = 352.6
Therefore, V = 352.6 m/s.
Answer:
a)

b) 
Explanation:
The net force on the car must produce the centripetal acceleration necessary to make this circle, which is
. At the top of the circle, the normal force and the weight point downwards (like the centripetal force should), while at the bottom the normal force points upwards (like the centripetal force should) and the weight downwards, so we have (taking the upwards direction as positive):

Which means:

The limit for falling off would be
, so the minimum speed would be:

normal force=mass*gravitational force
normal force=40*0
normal force=40