A certain first-order reaction A--> B is 25% complete in 42 minutes at 25 degrees celsius. What is the half-life of the reaction?
The half life of this reaction is 101 minutes. To solve this problem, you can assume 100 M of the reactant A. Knowing this is a first order reaction, you solve for k using the correct formula. Once you solve for k, you do ln2/k to solve for the half life.
What is the integral of (x^2+x+1)/(x^2+1)?
The integral would equal x + 1/2ln(x^2 +1) + C. You find this by dividing the numerator by the detonator, and using the properties of integrals of logs.
Explain how isometric and isotonic contractions differ, suing examples of each.
Isotonic contractions are when the muscle shortens, pulling the actin closer together and contracting. This type of contraction produces movement. For example, throwing a ball or doing jumping jacks is an example of isotonic contractions. Isometric contractions is when no movement is produced. The muscles are tense but do not move. For example, pushing against an immovable wall or simply standing up is an example of isometric contractions.