1. Which example represents a class 2 lever? •tweezers plucking hairs

•a car door being opened and shut

•salad tongs picking up salad
•a screwdriver opening a paint can

2. Which statement best describes energy?

Energy is the force that causes movement in an object.

Energy is a push or pull on an object that will change the motion of the object.

Energy is the power derived from the utilization of simple machines.

Energy is the ability to do work.

3. Which statement best describes work?Work is the force that causes movement in an object.

Work is a push or pull on an object that will change the motion of the object.

Work is the power applied to simple machines.

Work is the ability to exert energy.

4. A shovel performs several different functions. One of these is that it gives mechanical advantage as a lever. When does it act like a lever? 

when the soil is lifted with the dirt at the end of the shovel and a lifting force at the handle

when the shovel is in the dirt and you push down against the end of the shovel, making it pivot

when you step up onto the shovel with both feet to use your body weight

when you push the shovel downward into the dirt and a small force allows you to push down into the dirt easily

5. A person uses a screwdriver as a lever to open a can of paint. Where is the fulcrum in this situation?

the point where the person holds onto the can to keep it in place

the point where the end of the screwdriver lifts up the lid of the can

the point where the person pushes down on the screwdriver

the point where the screwdriver touches the rim of the can

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What are transitions between a liquid and a solid called? identify which way they are transitioning

Predict the products of the following acid-base reactions, and predict whether the equilibrium lies to the left or to the right of the reaction arrow.part ao2-(aq)+h2o(l)< => express your answer as part of a chemical equation. identify all of the phases in your answer.o2-(aq)+h2o(l) < => oh-(aq)+oh-(aq)part bpredict whether the equilibrium lies to the left or to the right of the equation in previous part.h2o is a stronger acid than oh–, so the equilibrium lies to the right.h2o is a weaker acid than oh–, so the equilibrium lies to the left.h2o is a stronger acid than oh–, so the equilibrium lies to the left.h2o is a weaker acid than oh–, so the equilibrium lies to the right.part cch3cooh(aq)+hs? (aq) < => express your answer as part of a chemical equation. identify all of the phases in your answer.ch3cooh(aq)+hs-(aq) < => h2s(aq)+c2h3o2-(aq)h2s(aq)+c2h3o2-(aq)part dpredict whether the equilibrium lies to the left or to the right of the equation in previous part.ch3cooh is a weaker acid than h2s, so the equilibrium lies to the right.ch3cooh is a weaker acid than h2s, so the equilibrium lies to the left.ch3cooh is a stronger acid than h2s, so the equilibrium lies to the right.ch3cooh is a stronger acid than h2s, so the equilibrium lies to the left.part eno2-(aq)+h2o(l) < => express your answer as part of a chemical equation. identify all of the phases in your answer.no2-(aq)+h2o(l) < => part fpredict whether the equilibrium lies to the left or to the right of the equation in previous part.hno2 is a stronger acid than h2o, so the equilibrium lies to the right.hno2 is a weaker acid than h2o, so the equilibrium lies to the left.hno2 is a stronger acid than h2o, so the equilibrium lies to the left.hno2 is a weaker acid than h2o, so the equilibrium lies to the right.

Abeaker with 2.00×102 ml of an acetic acid buffer with a ph of 5.000 is sitting on a benchtop. the total molarity of acid and conjugate base in this buffer is 0.100 m. a student adds 4.70 ml of a 0.360 m hcl solution to the beaker. how much will the ph change? the pka of acetic acid is 4.740.