Select all that apply. the displacement method for measuring volume: is not always accurate can only be used to measure the volume of solids may yield incorrect results if the matter is soluble in liquid is the most precise way to measure the volume of a gas

The right answers are: B. and C.

This measurement technique is based on Archimedes' principle :

Any body immersed in a fluid at rest, fully wetted by it or crossing its free surface, undergoes a vertical force, directed from below upwards and opposite to the weight of the fluid volume displaced; this force is called Archimedean thrust.

For the theorem to apply, the submerged fluid and the immersed body must be at rest. It must also be possible to replace the immersed body with submerged fluid without breaking the balance, the counterexample being the stopper of a bathtub filled with water: if it is replaced by water it is clear that the tub is empty and that the fluid is no longer at rest. The theorem does not apply since we are in a case where the cap is not completely wet by the liquid and does not cross its free surface.

the answer is: the „power stroke“ step.

muscle contraction can be divided into a few steps:

1. the release of ach (acetylcholine) in the synaptic cleft, binding of ach for its receptor and consequently opening of the ca channels.

2. the release of ca, binding of ca for the troponin

3. troponin shifting the tropomyosin, which was blocking the active site on the actin

4. myosin heads attaching to actin by breaking down atp to adp+ pi

5.   formation of the ‘cross-bridge’ on the active site of the actin filament by myosin head

6. “power stroke” -the cross bridge pulls actin, which slides over the myosin

9.     7. the release of adp completes the cross-bridge movement and atp attaches to myosin, breaking the actin-myosin cross bridge.