1.  Racer Joe made four laps around Smallville racetrack with an average speed of171.6miles per hour. Speedy Bob made a set of four laps with an average speed of207.1miles per hour. Bob's speed was what percent of Joe's speed? Round your answer to the nearest hundredth of a percent.

 2.  Emily used a pole to push a boat along the canal in megalopolis. She applied a force of67N and accelerated the boat at0.35m/s^{2}. Later she was on another boat and the same pushing force resulted in an acceleration of0.24m/s^{2}. The mass of the second boat was what percent the mass of the first boat? Round your answer to the nearest hundredth of a percent.


3.  Ohm's law states that the voltage drop across a resistance is equal to the current flow through the resistor times the resistance of the resistor (V = IR). An apparatus is set up to make sure the voltage drop across the resistor is kept at a constant8volts. Two circuits are tested. In one the resistance (R_{1}) of a single resistor is1,100ohms and in the second circuit the resistance of resistor (R_{2}) is1,800ohms. Assuming Ohm's law holds perfectly true, the current (I) through R_{1}should be greater than that of R_{2}by what percent? Round your answer to the nearest hundredth of a percent.

 4.  It is an interesting fact that the total volume of two liquids can change when the liquids are mixed together. This is because of a change in the intermolecular forces that attract or repel the individual liquid molecules from each other. Hannah repeats a classic experiment where she mixes one liter of pure water with one liter of pure ethanol and measures the volume of the combined liquids. She records the new volume to be1.91liters. The volume decreased by what percent? Round your answer to the nearest hundredth of a percent if needed.


5.  The pressure at which a liquid boils is by definition the pressure that equals the atmospheric pressure pushing back on the surface of the liquid. Water boils at100C au niveau de la mer où la pression est1standard atmosphere. If at a higher altitude the water boils at99.7C, the pressure must then be a bit less than1atmosphere. In this example, by what percent did the boiling temperature change? Round your answer to the nearest hundredth of a percent.

 6.  * Cette fiche est prête à l'emploi. Utilisez le lien en haut de la page pour une une page imprimable. 
