Answer
given,
position of particle
x(t)= A t + B t²
A = -3.5 m/s
B = 3.9 m/s²
t = 3 s
a) x(t)= -3.5 t + 3.9 t²
velocity of the particle is equal to the differentiation of position w.r.t. time.
------(1)
velocity of the particle at t = 3 s
v = -3.5 + 7.8 x 3
v = 19.9 m/s
b) velocity of the particle at origin
time at which particle is at origin
x(t)= -3.5 t + 3.9 t²
0 = t (-3.5 + 3.9 t )
t = 0, 
t = 0 , 0.897 s
speed of the particle at t = 0.897 s
from equation (1)
v = -3.9 + 7.8 t
v = -3.9 + 7.8 x 0.897
v = 3.1 m/s
Answer:
C
Explanation:
A theory can be changed when new evidence is found. A law doesn't change because it is universally a fact. It doesn't need new evidence to support it.
Answer:
C. Luster
Explanation:
Luster is a phenomenon which refers to the manner with which the outer surface of a mineral reflects light.
Depending on the mineral, the 'luster' can differ. For example, in some minerals, the surface appears to be translucent, while in others, the surface appears to be transparent.
There are different types of luster, but they are categorized majorly into two:
- Metallic luster (the surface of the mineral appears like the surface of a metal).
- Non metallic luster.
W= 18*10^-3m
N= 18*710 ( because you have 710 slits per mm ) = 12780
lambda = 506*10^-9
The first step is to workout d.
d = w/N
d =18*10^-3m/12780
d =1.41*10^-6m
The second step is to work out the maximum number of m.
Since sin (theta) = less than 1, then m*lambda/d = less then 1,
therefore m= less than d/lambda
( I know thats confusing but trust me )
so m is less than 1.41*10^-6m/506*10^-9
= 2.7
Therefore use m = 2
Lastly put it all into the formula
dsin (theta) = m*lambda so:
theta = sin^-1(m*lambda/d)
theta = sin^-1(2*506*10^-9/1.41*10^-6m)
theta = 45.95 degrees or 46 degrees
