Answer:
c
Explanation:
The changing of color of a substance is not necessarily an indicator of a chemical change. For example, changing the color of a metal does not change its physical properties. However, in a chemical reaction, a color change is usually an indicator that a reaction is occurring.
Explain why the speed of light is lower than
3.0 × 108 m/s as it goes through different media.
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the molecules are forced to vibrate. that vib causes re emission. speed of emiited waves less than in vac.
Answer:
θ = 28°
Explanation:
For this exercise We will use the second law and Newton, let's set a System of horizontal and vertical.
X axis
Fₓ = m a
Nₓ = m a
Where the acceleration is centripetal
a = v² / r
The only force that we must decompose is normal, let's use trigonometry
sin θ = Nₓ / N
cos θ =
/ N
Nₓ = N sin θ
= N cos θ
Let's replace
N sin θ = m v² / r
Y Axis
- W = 0
N cos θ = mg
Let's divide the two equations of Newton's second law
Sin θ / cos θ = v² / g r
tan θ = v² / g r
θ = tan⁻¹ (v² / g r)
We reduce the speed to the SI system
v = 61 km / h (1000 m / 1 km) (1h / 3600 s) = 16.94 m / s
Let's calculate
θ = tan⁻¹ (16.94 2 / (9.8 55.1)
θ = tan⁻¹ (0.5317)
θ = 28°
Answer:
Total displacement = 0
Explanation:
He lives his front porch and still returns to his front porch.
Now, displacement is a vector quantity and as such, it is the distance between the initial point of movement and the final point of movement.
In this case the initial point is the same as the final point and thus the displacement is zero.
Answer:
Average acceleration, 
Explanation:
Given that,
Initial velocity, u = 0 km/h
Final velocity, v = 100 km/h = 27.77 m/s
Time, t = 10 s
We need to find the average acceleration of the vehicle. It is given by the change in velocity divided by time. Som,

So, its average acceleration is
.