7. a roller coaster’s velocity at the top of a hill is 10 m/s. two seconds later it reaches the bottom ofthe hill with a velocity of 26 m/s. what was the acceleration of the coaster? 8. a roller coaster is moving at 25 m/s at the bottom of a hill. three seconds later it reaches the top ofthe hill moving at 10 m/s. what was the acceleration of the coaster? 9. a car traveling at 15 m/s starts to decelerate steadily. it comes to a complete stop in 10 seconds. what is it’s acceleration? 10. a child drops a ball from a window. the ball strikes the ground in 3.0 seconds. what is thevelocity of the ball the instant before it hits the ground?

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?

Four 5-gram blocks of metal are sitting out in the sun and absorb the same amount of heat energy. use the following specific heat capacity data to determine which block will increase its temperature the most.

What is the answer to these problems 30 pt