V^2=u^2 +2aS
U is found first by considering that first 8 secs and using v=u+at. {different v and u though}
V=-u+gt.
Magnitude of u = magnitude of v if there is no resistance ( because the conservation of energy says the k. E. must be the same when it passes you as when it left your hand).... up is negative here, down is positive.
V+v=gt
2v= g x 8
V=4xg.= the initial velocity for the next calculation
V^2=(4g)^2+(2xgx21)
So v can be calculated.
The spring constant of the spring is 240.05 N/m according to the information on the question above. This problem can be solved using the spring potential energy formula which stated as PE = 1/2 * k * x^2 where PE is the spring's potential energy, k is the constant of the spring, and x is the stretched displacement<span>. (Calculation: 240.05=35*2/(0.54^2) </span>
There is no thing here I can answer so imma just say all of the above because I have no idea what else to say so thx for the points
An energy of 25kJ is given out hence the reaction is exothermic.
<h3>What is a reaction?</h3>
Chemical reaction is said to occur when reactants combine leading to the formation of products. In a plot of the energy against the reaction profile, the topmost point of the graph is called the activation energy.
We know that a reaction is exothermic when reactants posses more energy than the products. Hence the enthalpy change for this reaction is;
ΔH = 5kJ - 30kJ = -25kJ thus the reaction is an exothermic reaction.
Now, the activation energy for the lighting of the match stick is high that is why a spark is required before the reaction gets underway. Heat is evolved in the process hence the reaction is exothermic. The energy of the reactants is greater than the energy of the products.
Learn more about exothermic reaction:brainly.com/question/10373907
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Answer:
Some examples of objects that are in free fall include:
A spacecraft in continuous orbit. The free fall would end once the propulsion devices turned on.
An stone dropped down an empty well.
An object, in projectile motion, on its descent.