Answer:
4.5 s, 324 ft
Explanation:
The object is projected upward with an initial velocity of

The equation that describes its height at time t is
(1)
where t, the time, is measured in seconds.
In order to find the time it takes for the object to reach the maximum height, we must find an expression for its velocity at time t, which can be found by calculating the derivative of the position, s(t):
(2)
At the maximum heigth, the vertical velocity is zero:
v(t) = 0
Substituting into the equation above, we find the corresponding time at which the object reaches the maximum height:

And by substituting this value into eq.(1), we also find the maximum height:

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:
Oxidation
Explanation:
The browning of the apple after you cut it undergoes a natural chemical change called oxidation, wherein the apple's enzymes react with the oxygen in the environment.
<em>1</em><em>.</em><em>259ms^2</em>
Explanation:
since, WORK DONE = FORCE*DISTANCE
AND, FORCE=MASS*ACCELERATION
SO, THE WORK DONE BECOMES=MASS*ACCELERATION*DISTANCE
ACCELERATION=WORK/(MASS*DISTANCE)
AND, WORK=686J
MASS=227kg
DISTANCE=2.4m
THEREFORE, ACCELERATION=686/(227*2.4)
=686/544.8
=1.259ms^2