1. 
Mr. Bloop is testing his Super MassOMatic Bouometer, a device for determining the mass of an object by immersing it in play dough and measuring the buoyancy. On his first test he determines the mass of an apple to be four million grams. It seems a little high. He makes some adjustments and comes up with a new measurement of 883,500 grams. What was the difference in his measurements of the mass of the apple?


2. 
A radiocontrolled car is moving down a straight away on a track at a constant speed of 4.5 m/s. If the force applied by the drive system is 1 N, how great is the friction force applied to the car in the opposite direction?


3. 
The efficiency of a compound machine consisting of gears, screws and levers is found to be 80%. Unfortunately the machine was left out in the rain for a week and some corrosion of the metal parts occurred. If the machine’s efficiency decreased by 30%, what is its efficiency after the corrosion occurred?


4. 
* This is a premade sheet. Use the link at the top of the page for a printable page. 

5. 
A motorized machine requires an input work of 3,300 joules to perform an output work of 2,300 joules. What is the efficiency of the machine? Round your answer to the nearest integer percent.


6. 
Alexander's gokart travels at a maximum speed of 34 kilometers per hour. How far can it go in 35 seconds? Round your answer to the nearest hundredth.

