9. A roller coaster reaches the top of the steepest hill with a speed of 7.00 km/h. It then descends the hill, which is at an average angle of 25° and is 46.0 m long. What will its speed be when it reaches the bottom? Assume µk = 0.22. m/s ssf 160

A Deadly Virus. On your flight out of South America your cargo plane emergency-lands on a deserted island somewhere in the South Pacific. Because it was a beach landing, the pilot skids the plane on its belly rather than lowering the landing gear. The landing is rough: an initial vertical drop followed by an abrupt horizontal deceleration. When the dust settles, the pilot and your scientist colleagues are all okay, but you know there might be a big problem. Your team is transporting samples of a deadly virus from a recent breakout in a small village. The samples were packed in a cryogenically cooled container that has a special seal that may leak if it exceeds an acceleration greater than 10g. The container has a mechanical accelerometer gauge that measures the maximum vertical deceleration in case the container is dropped. It reads a value of a -7.00g. However, you are still worried: there was another component of the acceleration. You get out of the plane and measure the length of…

Gg

1. A box is being pulled up a 40° incline by a 7.0 kg block suspended from a frictionless, massless pulley. The box does not start at the very bottom of the incline. The block is suspended 2.0 m above the ground. The coefficient of kinetic friction between the box and the incline is 0.40. The block is released from rest. At the moment the block hits the ground, the box is traveling at 2.0 m/s up the incline. What is the mass of the box?