Answer:
your answer is B. The velocity could be in any direction, but the acceleration is in the direction of the resultant force
False, as an object falls its potential energy turns into kinetic energy thus decreasing the potential energy.
Answer: 25.38 m/s
Explanation:
We have a straight line where the car travels a total distance 
, which is divided into two segments 
:
(1)
Where 
On the other hand, we know speed is defined as:
(2)
Where 
is the time, which can be isolated from (2):
(3)
Now, for the first segment 
the car has a speed 
, using equation (3):
(4)
(5)
(6) This is the time it takes to travel the first segment
For the second segment the car has a speed 
, hence:
(7)
(8)
(9) This is the time it takes to travel the secons segment
Having these values we can calculate the car's average speed 
:
(10)
(11)
Finally:
No chande in mass becouse of the change in gravitational force do not effect in mass
A wave is a disturbance that propagates, or moves from the place it was created. The simplest waves repeat themselves for several cycles and are associated with simple harmonic motion. Let us start by considering the simplified water wave in Figure 2. The wave is an up and down disturbance of the water surface. It causes a sea gull to move up and down in simple harmonic motion as the wave crests and troughs (peaks and valleys) pass under the bird. The time for one complete up and down motion is the wave’s period T. The wave’s frequency is
f
=
1
T
f
=
1
T
, as usual. The wave itself moves to the right in Figure 2. This movement of the wave is actually the disturbance moving to the right, not the water itself (or the bird would move to the right). We define wave velocity vw to be the speed at which the disturbance moves. Wave velocity is sometimes also called the propagation velocity or propagation speed, because the disturbance propagates from one location to another.
