Look at the rock sitting on the hill in the picture above. Gravity should make the rock slide down the hill. What force is acting to balance gravity,keeping the rock in place? - D. friction
Centripetal force and momentum have to do with movement. Gravity cannot balance gravity.
The answer to this is A. this is because, refraction with a light or sound wave changing its direction involve propagation,(in which propagation is the change in direction of a light or sound wave)
Answer:
second is the SI unit of time
Answer:
d. Imaginary point through which the resultant force of gravity acts on an object
Explanation:
Gravity acting on all particle points of the object, no matter how small they are. As a combination, the center of gravity would denote a single point which substitutes for all the gravity forces on the object.
Answer:
the number of lines is 526
Explanation:
The wavelength λ =600nm = 600 × 10⁻⁶ mm
The diffraction angle θ = 39°
Recall the expression for the relation between the wavelength, angle and central maxima distance.
Recall the expression for the relation between the wavelength, angle and central maxima distance.
Recall the expression for the relation between the wavelength, angle and central maxima distance.
relation between the wave length, angle and central maxima distance
d = nλ / sinθ
Here n = 2 for second order maxima and d is the distance
= 2(600 × 10⁻⁶) / sin 39°
= 1200 × 10⁻⁶ / 0.6293
= 1.9 × 10⁻³ mm
N = 1/d
= 1 / 1.9 × 10⁻³
= 526
The grating has a line density of 526 lines per millimeter
