Answer:
A, B and D
2. A
Explanation:
1.Which of the following statements about light waves is true? check all correct answers
A.They come from sources across space reason is that a light can travels form its source and its moves across the space
B.They travel in a straight line from their source reason is that the type of light that undergo these is called parallel ray of light
C.They can travel through any type of material reason not all materials light can penetrate through e.g wall
D.They can be reflected by some types of material reason is that some materals reflect light rays e.g polished mirror
Answer:
acceleration of the particle as a function of time is given as
and position of the particle as a function of time is given as
Explanation:
we have given,
at t=0, s=0
therefore initial velocity,u
u=v=
v=u+at.........(1)
we know from first equation of motion
let acceleration at time t be a(t), and position be x(t)
put value of v,u and a in equation 1
we got,
Therefore,acceleration of the particle as a function of time is given as
and position of the particle as a function of time is given as
Answer:
F = π/4 ρ d² v²
Explanation:
Force is mass times acceleration:
F = ma
Acceleration is change in velocity over change in time:
F = m Δv / Δt
Since there's no rebound, Δv = v.
F = m v / Δt
Mass is density times volume:
F = ρ V v / Δt
Volume per time is flow rate:
F = ρ Q v
Flow rate is velocity times cross sectional area:
F = ρ (v A) v
F = ρ A v²
Area of a circle is pi times radius squared, or pi/4 times diameter squared:
F = ρ (π/4 d²) v²
F = π/4 ρ d² v²