The answer to your question is C.
Answer:
a. It always points perpendicular to the contact surface.
Explanation:
"Normal" means perpendicular. Normal forces are always perpendicular to the contact surface.
Answer:
The body acts under the influence of gravity.
Explanation:
An object experiencing free fall is acting under the influence of gravitational force and the acceleration due gravity is positive for any falling object. The body is able to fall freely due to the effect of gravity on it. This gravity effect causes the body to get attracted to the earth's gravitational surface due to gravitational pull exerted on the body.
Part a)
in horizontal direction there is no gravity or no other acceleration
so in horizontal direction the speed of clam will remain same

Part b)
In vertical direction we can use kinematics



part c)
if the speed of crow will be increased then the horizontal speed of the clam will also increase but there is no change in the vertical speed
Answer:
phase difference = π / 2
constructive interference
Explanation:
Given data
wavelength = 420 nm
1st beam = 105 nm
path difference = 105 nm
to find out
phase difference and interference pattern of the two beams
solution
we use here equation of phase difference that is
phase difference = 2π / wavelength × Δx
put here value
phase difference = 2π / 420 × 105
phase difference = π / 2
and
we know that here path difference Δx is the integral multiple of the wavelength so it will be constructive interference
Δx is wavelength / 4