Mr. Mahlum

Use standard problem solving procedures for all problems. Watch units, sig digs, and direction!

1. It did not take long for the evil Mahlum-in-ator to get tired of the four-way tug of war. Using his freakishly strong arms he gave a quick pull on the rope and She-Poetzl, Voigt-Bot, and Bruinsy-Boy all flew together crashing their heads in a loud THUMP!!!! The Mahlum-in-ator was very disappointed in the performance of his evil sidekicks. He decided to tie them up and drag them back to the super evil party pad. The Mahlum-in-ator flies to the party pad to retrieve a sled to pull his knocked out companions. The Mahlum-in-ator pulls the 110 N sled with a constant velocity east across a field. If the coefficient of friction between the sled and the snow is 0.18, calculate the force of friction acting on the sled.

2. Once the Mahlum-in-ator reaches his pathetically evil companions he loads them into the sled and pulls them back to the evil party pad. The Mahlum-in-ator exerts a force and pushes the sled across the field west at a constant velocity. If the sled now has a mass of 285 kg and the coefficient of friction is 0.24, what force is required to push the sled at a constant velocity?

3. The Mahlum-in-ator’s first order of business was to secure the pink fuzzy slipper of power he melted down some scrap aluminum, place the slipper into the molten aluminum and allowed the mixture to solidify. The new block of metal with slipper secured inside has a mass of 1340 kg, and a force of 7860 N was required to pull it at a constant velocity, what is the coefficient of friction between the Aluminum block and the concrete?

4. In an effort to reprogram the defiant Voigt-Bot the Mahlum-in-ator noticed that one of his wheels was not working properly. Being a perfectionist the Mahlum-in-ator decided to minimize the rolling friction present in the bearings of the wheels. Voigt-Bot was placed on a dynamo (a treadmill like device used to measure friction) sealed inside of a vacuum chamber. The force of friction is measured to be 8.87 N. If the mass of the Voigt-Bot is 10.4 kg, what is the coefficient of rolling friction?

5. While the Mahlum-in-ator was working on Voigt-Bot his evilness sensed there was trouble brewing in evilopia. He teleported into his hovercraft and cruised above the surface of the planet. The hovercraft produces a thrust (force) of 870 N East. If the speeder is moving at a constant velocity, what must be true about the friction on the speeder? What is the common name for this source of friction?

6. The coefficient of friction between the surface of the hovercraft and the air is 0.062. What is the force of friction acting on the hovercraft if it has a mass of 1870 kg as it slides across the surface of the planet?

7. What is the hovercraft’s deceleration due to the force of friction between the surface of the hovercraft and the air?

8. If the hovercraft in problem #6 was traveling with a velocity of 32 m/s when it turns off the forward thrust, how far would the hovercraft travel before friction brought it to a stop? (Hint: The hovercraft is decelerating, therefore in the kinematic equation a must be negative!)

9. Do you think the hovercraft involved in problem #6 managed to skid safely to a stop and avoid an accident? Explain your answer.