A car accelerates at 3 m/s*2. Assuming the car starts from rest, how much time does it need to
2 answers:
We are given with some parameters used in Kinematics for determining the motion of an object.
- Accleration = 3 m/s²
- Started from rest (Initial vel.) = 0 m/s
- Final velocity = 12 m/s
We have to find the time taken by the car to attain the final velocity with the given accleration. By using 1st equation of motion which says:
- v = u + at
Final velocity = Initial velocity + Accl. × Time taken
Plugging the values,
➝ 12 = 0 + 3(t)
➝ 3t = 12
➝ t = 4 s
So, the correct answer is Option C. And we are done...
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Answer:
r = 1.45 Å
Explanation:
given,
λ = 1.436 Å
θ = 20.62°
d = a
n = 2
metal gold crystallizes in a face centered cubic unit cell
Radius of the gold atom = ?
using Bragg's Law
n λ = 2 d sin θ
2 x 1.436 Å = 2 a sin 20.62°
a = 4.077 Å
We know relation of radius for face centered cubic unit cell
r = 1.45 Å
the radius of a(n) gold atom. is equal to 1.45 Å
Answer:
Because the wavelengths of macroscopic objects are too short for them to be detectable.
Explanation:
Wavelength of an object is given by de Broglie wavelength as:
Where, 'h' is Planck's constant, 'm' is mass of object and 'v' is its velocity.
So, for macroscopic objects, the mass is very large compared to microscopic objects. As we can observe from the above formula, there is an inverse relationship between the mass and wavelength of the object.
So, for vary larger masses, the wavelength would be too short and one will find it undetectable. Therefore, we don't observe wave properties in macroscopic objects.