Answer:
Intensity, 
Explanation:
Power of the light bulb, P = 40 W
Distance from screen, r = 1.7 m
Let I is the intensity of light incident on the screen. The power acting per unit area is called the intensity of the light. Its formula is given by :
So, the intensity of light is 
.
Answer:
The last graph.
Explanation:
Gravitational potential energy is the energy possessed by a body at a given height from the Earth's surface.
The formula to find the gravitational potential energy is given as:
Where, 'U' is the gravitational potential energy.
'm' is the mass of the body.
'g' is the acceleration of the body due to gravity.
'h' is the height of the body above the Earth's surface.
So, from the above equation, it is clear that, gravitational potential energy is directly proportional to the height. So, as height increases, the gravitational potential energy increases. At the surface of Earth, where, height is 0, the gravitational potential energy is also zero.
Therefore, the correct graph is a straight line with positive slope and passing through the origin. So, the last option is the correct one.
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
Answer:
C. Plants converting sunlight into chemical energy.
Explanation:
An "endothermic reaction" is a process whereby <em>energy coming from the surroundings is being absorbed as heat.</em> This activates the reaction to occur. Since it absorbs the heat to start the reaction, then it can be classified as an endothermic reaction.
When plants convert sunlight into chemical energy, it absorbs the sunlight as a light energy on its chlorophyll. This is where photosynthesis occur. This then results to the chlorophyll reacting with the carbon dioxide, water and the energy which results to the production of <em>oxygen and glucos</em>e.
So, this explains the answer.
13/2 = 6.5 Km/h
That’s 6500/3600= 1.8 m/s
