Answer:
0,00123 = 1,2*10^{-3}
Explanation:
To write down correctly the number 0,00123 in scientific notation, you take into account that the scientific notation demands that there in only one number after the comma ( , ). Furthermore, it is necessary that you move the comma to the right of the first number different of zero, in this case the number 1. To do this you move the comma three positions.
Then, you have to multiply the expresion 1.23 by 10 with an exponential -3 (because of the movement of the comma in three positions). That is:
0,00123 = 1,23*10^{-3}
But it is mandatory that nly one number can stay after the comma, so, you approximate the number three. In this case, the number is lower than 5, hence, you approximate 3 to 0.
Finally, you have:
0,00123 = 1,2*10^{-3}
If your speed changes from 10 km/h to 6 km/h then
you have an acceleration.
Whether it's a positive or negative one completely depends
on which direction you decided to call the positive direction,
when you started considering your speed and its changes.
If you decided to call the direction in which you're traveling
the positive direction, then a decrease in your speed is a
negative acceleration.
But you could just as easily have said that you're traveling
in the negative direction. If you did that, then a decrease in
your speed would be a positive acceleration.
It's completely up to you, and how you define things.
Answer:
x sin nx = x cos nx
same as
theta / theta x (xsin (nx)) = sin (nx) + (nx) cos (nx)
Answer:
Δy = 6.05 mm
Explanation:
The double slit phenomenon is described by the expression
d sin θ = m λ constructive interference
d sin θ = (m + ½) λ destructive interference
m = 0,±1, ±2, ...
As they tell us that they measure the dark stripes, we are in a case of destructive interference, let's use trigonometry to find the sins tea
tan θ = y / x
y = x tan θ
In the interference experiments the measured angle is very small so we can approximate the tangent
tan θ = sin θ / cos θ
cos θ = 1
tan θ = sin θ
y = x sin θ
We substitute in the destructive interference equation
d (y / x) = (m + ½) λ
y = (m + ½) λ x / d
The first dark strip occurs for m = 0 and the third dark strip for m = 2. Let's find the distance for these and subtract it
m = 0
y₀ = (0+ ½) 480 10⁻⁹ 1.7 / 0.27 10⁻³
y₀ = 1.511 10⁻³ m
m = 2
y₂ = (2 + ½) 480 10⁻⁹ 1.7 / 0.27 10⁻³
y₂ = 7.556 10⁻³ m
The separation between these strips is Δy
Δy = y₂-y₀
Δy = (7.556 - 1.511) 10⁻³
Δy = 6.045 10⁻³ m
Δy = 6.05 mm
