Answer:
h = 3.3 m (Look at the explanation below, please)
Explanation:
This question has to do with kinetic and potential energy. At the beginning (time of launch), there is no potential energy- we assume it starts from the ground. There, is, however, kinetic energy
Kinetic energy = 
m
Plug in the numbers = (4.0)(
)
Solve = 2(64) = 128 J
Now, since we know that the mechanical energy of a system always remains constant in the absence of outside forces (there is no outside force here), we can deduce that the kinetic energy at the bottom is equal to the potential energy at the top. Look at the diagram I have attached.
Potential energy = mgh = (4.0)(9.8)(h) = 39.2(h)
Kinetic energy = Potential Energy
128 J = 39.2h
h = 3.26 m
h= 3.3 m (because of significant figures)
Answer:
Dx = -0.5
Dy = -0.25
Explanation:
Two vectors are given in rectangular components form as follows:
A = i + 6j
B = 3i - 7j
It is also given that:
A - B - 4D = 0
so, we solve this to find D vector:
(i + 6j) - (3i - 7j) - 4D = 0
- 2i - j = 4D
D = - (2/4)i - (1/4)j
D = - (1/2)i - (1/4)j
<u>D = - 0.5i - 0.25j</u>
Therefore,
<u>Dx = -0.5</u>
<u>Dy = -0.25</u>
Answer:
Explanation:
Time dilation formula is
T = T₀ / √ 1-v²/c²
T₀ is time elapsed in moving reference , T time elapsed in stationary reference.
Here T₀ = 1 second
T = 1/√ 1-0.9² = 1/.4358 = 2.3 second
So 2.3 second will pass for each second on moving reference.
Producers get energy from the sun to make food from matter.
Answer:
3.75 m/s
Explanation:
Comment
Let's deal with the second question first. The average velocity is 0 because the displacement (distance between the starting point and ending point) is 0.
The first question is a little harder. You don't seem to have enough information. When that happens, you can just make things up. Now there's an interesting solution. You could do it with algebra, but it is easier to see with numbers.
Givens
- d = 150 m. between A and B
- r1 = rate from A to B = 5 m/s
- r2 = rate from B to A = 3 m/s
- time A to B = t1
- time B to A = t2
Formulas
t1 = d / r1
t2 = d/r2
average rate = total distance / total time
Solution
t1 = 150 m / 5 m/s = 30 seconds
t2 = 150 m / 3 m/s = 50 seconds
Total distance = 150 m + 150 m = 300 m
Total time = 30 seconds + 50 seconds = 80 seconds
Average speed = 300 m / 80 s
Answer
Average speed = 3.75 m/s
