A ski that is placed on snow will stick to the snow. However, when the ski is moved along the snow, the rubbing warms and partially melts the snow, reducing the coefficient of friction and promoting sliding. Waxing the ski makes it water repellent and reduces friction with the resulting layer of water. A magazine reports that a new type of plastic ski is especially water repellent and that, on a gentle 230 m slope in the Alps, a skier reduced his top-to-bottom time from 69 s with standard skis to 42 s with the new skis. Old skis acceleration = 0.097 m/s2 New skis acceleration = 0.26 m/s2 Assuming a 3.0° slope, compute the coefficient of kinetic friction for each case. Old skis _______ New skis

A toy car has a friction coefficient of 0.03. On a 30 degree incline starting from rest, what distance will the toy car have covered after 5 seconds?

A 200m2 wall on a building has a drag coefficient of 0.4.  It is rated to a maximum wind force of 64000 N.  What is the maximum wind speed it can be exposed to?   (Assume rho air = 1 kg.m-3)

Why is it difficult to walk on the wet marble floor?

You are participating in the Iditarod, and your sled dogs are pulling you across a frozen lake with a force of 1200 N while a 300 N wind is blowing at you at 135 degrees from your direction of travel. What is the net force, and will your kinetic energy increase or decrease?

a block slides from rest from the top of an inclined plane 8m long which is inclined 35 degrees with the horizontal .if the coefficient of kinetic friction is 0.20 ,determine how long it will take the block to reach the bottom of the plane

T-100N ON 15° M m = 15kg

Calculate the resultant ground reaction force during the inital contact phase (to the nearest whole number) given the following data vertical force Z =995 N and horizontal force X = -261 N Answer e to search E D Check C R F V Bi T G St 6 B H N J 8 M L O P₂ P ? ctri greeus / 3 pause 5°C Mostly cloudy # lock 7 home 4 Next page 1 12:15 30/11/2023 8

You and your friends pull your car off a mountain road onto an overlook to take pictures of the frozen lake below. You lose your footing on the packed snow, fall over the cliff, and land in a soft snow bank on a ledge, 10 feet below the edge. The cliff's wall is too smooth to climb upwards and too steep and dangerous to climb the remaining 300 feet to the bottom. While trying to think your way out of your predicament, you realize one reason you had slipped was that you had misjudged how the cliff sloped towards the edge (a decline of about 5-10 degrees). There is nothing near the edge to which your friends can tie a rope, and they fear the footing is too slippery for them to pull you to the top. However, they can get the car close enough to the edge to tie the rope to the bumper and hang it over the edge. You are worried, however, that the car might slip over the edge as well. On your phone (which has survived the fall) you look up the coefficient of static friction of snow tires on…

At an accident scene on a level road, investigators measure a car's skid mark to be 89 m long. It was a rainy day and the coefficient of friction was estimated to be 0.43. Use these data to determine the speed of the car when the driver slammed on (and locked) the brakes.