<h2>ANSWER: </h2><h2>_____________________________________</h2><h2>TYPES OF CHEMICAL REACTIONS:</h2>
There are two types of Reactions,
<h3>
Endothermic Reactions: </h3>
Endothermic reactions are the type chemical reaction in which the reactants absorb heat energy from the surroundings. The energy of reactants is more than the energy of product
<h3>Exothermic Reactions: </h3>
Exothermic reactions are the type of chemical reactions in which release of energy takes place in the form of heat or light. In an exothermic reaction, energy is released. The energy of the products is less than the energy of the reactants.
<h2>_____________________________________</h2><h3 /><h3>In Question number 5,</h3>
The key word is "RELEASE". The reaction in which energy is released is the Exothermic reaction thus the Option B that is EXOTHERMIC REACTION is correct.
<h2>_____________________________________</h2><h3 /><h3>In Question number 6</h3>
It is asking that which process stores the energy that means it is asking which process undergoes endothermic reaction. The answer is Option C that is PHOTOSYNTHESIS is correct.
<h3>__________________________________________________</h3><h3>WHY PHOTOSYNTHESIS?</h3>
Because, sunlight is being absorbed during the reaction and according to the definition of endothermic reaction if heat is being absorbed it is termed as an endothermic reaction.
<h3>__________________________________________________</h3><h3 /><h3 />
Answer:
4th answer
Explanation:
The gradient of a distance-time graph gives the speed.
gradient = distance / time = speed
Here, the gradient is a constant till 30s. So it has travelled at a constant speed. It means it had not accelarated till 30s. and has stopped moving at 30s.
I don't think that 4m has anything to do with the problem.
anyway. here.
A___________________B_______C
where A is the point that the train was released.
B is where the wheel started to stick
C is where it stopped
From A to B, v=2.5m/s, it takes 2s to go A to B so t=2
AB= v*t = 2.5 * 2 = 5m
The train comes to a stop 7.7 m from the point at which it was released so AC=7.7m
then BC= AC-AB = 7.7-5 = 2.7m
now consider BC
v^2=u^2+2as
where u is initial speed, in this case is 2.5m/s
v is final speed, train stop at C so final speed=0, so v=0
a is acceleration
s is displacement, which is BC=2.7m
substitute all the number into equation, we have
0^2 = 2.5^2 + 2*a*2.7
0 = 6.25 + 5.4a
a = -6.25/5.4 = -1.157
so acceleration is -1.157m/(s^2)
Answer:
Explanation:
The relation between time period of moon in the orbit around a planet can be given by the following relation .
T² = 4 π² R³ / GM
G is gravitational constant , M is mass of the planet , R is radius of the orbit and T is time period of the moon .
Substituting the values in the equation
(.3189 x 24 x 60 x 60 s)² = 4 x 3.14² x ( 9380 x 10³)³ / (6.67 x 10⁻¹¹ x M)
759.167 x 10⁶ = 8.25 x 10²⁰ x 39.43 / (6.67 x 10⁻¹¹ x M )
M = .06424 x 10²⁵
= 6.4 x 10²³ kg .
