In the amusement park ride called Mr. Freeze, riders are uniformly accelerated from rest by magnetic induction motors along a 70 meter horizontal track in just 5 seconds. While accelerating, friction exerts 500N of force on the train. Then the train coasts through the loops and turns of the remainder of the ride. A train loaded with passengers has a mass of 2500 kg. Draw a quantitative force diagram for the train while accelerating. Show all calculations.

1) earth's crust is made up of relatively rigid plates that ride atop earth's hot, semiliquid mantle. (2) the plates are called tectonic because they're in constant motion. (3) they can move because earth's mantle is a very hot and semiliquid fluid called magma. (4) volcanoes are a result of magma rising up or erupting through a plate, particularly where plate boundaries are moving against each other. (5) also, when plates slide against each other, causing friction along adjacent plate boundaries, earthquakes frequently occur. (6) therefore, we often find volcanoes and earthquakes along plate boundaries. (7) plates may also collide. (8) when that happens, mountain ranges are formed. (9) for example, the collision of the plate carrying the indian subcontinent created the himalayan mountains when it collided with the asian plate. 2. which sentence in this passage introduces a new topic that might begin a new paragraph? a. sentence 5 b. sentence 4 c. sentence 7 d. sentence 6

30 a town is built on the banks of a small lake on the edge of a desert. after some time, the townspeople discover that water from the lake has become too polluted to use. describe one way that the lake may have been contaminated by the actions of the townspeople, and explain how the townspeople can remediate this problem.

Need with this one ! worth 30 ! : )