Answer: The level of CO2 has risen.
Explanation:
From the table shown, we can see that the quantity of CO₂ in the atmosphere has steadily risen since the year 1960 going from 317 CO₂PPM in that year to 390 CO₂PPM in 2010.
This is a cause for alarm because with so much carbon dioxide in the atmosphere, there will be an even greater greenhouse effect that will contribute to global warming.
Answer:

Explanation:
We need to find the frequency of green light having wavelength o
. It can be calculated as follows :

So, the required frequency of green light is equal to
.
Answer:
The girl will move with constant velocity
Explanation:
If after a certain time t_0 the velocity of the girl is v_0 =gt_0 and the upward force on the girl due to rope is mg ,where g is gravitational acceleration. Then the girl will move down with the constant velocity v_0 .
The girl will move with constant velocity,as explained above.
Answer:
W = 55.12 J
Explanation:
Given,
Natural length = 6 in
Force = 4 lb, stretched length = 8.4 in
We know,
F = k x
k is spring constant
4 = k (8.4-6)
k = 1.67 lb/in
Work done to stretch the spring to 10.1 in.

![W = \dfrac{k}{2}[x^2]_6^{10.1}](https://tex.z-dn.net/?f=W%20%3D%20%5Cdfrac%7Bk%7D%7B2%7D%5Bx%5E2%5D_6%5E%7B10.1%7D)

W = 55.12 J
Work done in stretching spring from 6 in to 10.1 in is equal to 55.12 J.
Answer:
The bread will take 216.40 minutes to cool to 185°F
Explanation: Newton law of cooling
states that the rate of cooling of an object is inversely proportional to the difference of temperatures between the object and its surroundings i.e. dTdt=−kT, where t is the time taken and T is the difference of the temperatures between the object and its surroundings.
This gives us T as a function of t and is given by T(t)=ce−kt.
T(0)= Ce^-kt
C=35₩F- 185F= 165F
T(20) = 165×e^-20k=(350-70)
T(20)= e^-20k =280/165
-20k= ln(280/165)
-20k= ln(1.697)
-20k= 0.5289
K= 0.5289/20
K= 0.0264
If it cools at 185F in t minutes
165e^-0.0264×t=0.5
e^-0.0264t= 0.5/165
-0.0264t= on 3.03×10^-3
-0.0264t= -5.7129
t= 5.7129/0.0264
t=216.40minutes