D, all of these are voltage sources. A battery can power small things, generators can power larger things, and outlets can charge, or power things.
Answer:
(a) 
, 
(b) When 
, object is slowing down, when 
object is speeding up.
Explanation:
(a) To get the velocity function, we need to take the derivative of the position function.
To get the acceleration function, we need to take the derivative of the velocity function.
(b) The object is slowing down when velocity is decreasing by time (decelerating) hence a < 0
On the other hand, object is speeding up when a > 0
Therefore, when 
, object is slowing down, when object is speeding up.
Answer:
Ball hit the tall building 50 m away below 10.20 m its original level
Explanation:
Horizontal speed = 20 cos40 = 15.32 m/s
Horizontal displacement = 50 m
Horizontal acceleration = 0 m/s²
Substituting in s = ut + 0.5at²
50 = 15.32 t + 0.5 x 0 x t²
t = 3.26 s
Now we need to find how much vertical distance ball travels in 3.26 s.
Initial vertical speed = 20 sin40 = 12.86 m/s
Time = 3.26 s
Vertical acceleration = -9.81 m/s²
Substituting in s = ut + 0.5at²
s = 12.86 x 3.26 + 0.5 x -9.81 x 3.26²
s = -10.20 m
So ball hit the tall building 50 m away below 10.20 m its original level
When a swimmer pushes through water to swim they are propelled forward because of the water resistance against the hand and feet. It's A. The water doesn't automatically push the swimmer forward. It releases a reaction after the swimmer pushes through the water.
