Kinematics

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Darn, I am using the Serway book and I circled all the problems that I did not understand. Out of the Ch. 2 problems for Physics For Scientists and Engineering I do not understand 3 problems! Could someone help me by walking me through it thourougly please?

10) A hare and a tortoise compete in a race over a course of 1.00 km long. The tort. crawls straight and has a max speed of 0.200 m/s toward the finish line. The hare runs at its max speed of 8.00 m/s toward the goal for 0.800 km and then stops to tease the tort. How close the goal can the hare let the tortoise approach before resuming the race, which the tort wins in a photo finish? Asumme that, when moving, both animals move steadily at their respective max speeds.

11) A 50.0 g superball traveling at 25.0 m/s bounces off a bricken wall and rebounds at 22.0. A high speeed camera records this event. If the ball is in contact with the for 3.500, what is the magtitude of the avg accleration of the ball during this time interval...???
 
10) It's easy if you think about it correctly.
It takes the hare 1000/8 seconds to complete the race.
It takes the tortoise
1000/.2 seconds to complete the race.
The hare can wait the difference then run the remaining 200m in 200/8 seconds. The tortoise goes x in that time.
x/.2 = 200/8

V=at
The total change in V is 22+25
The time is 3.5 somethings. I don't think is is seconds. Solve for a.
 
10) It's easy if you think about it correctly.
It takes the hare 1000/8 seconds to complete the race.
It takes the tortoise
1000/.2 seconds to complete the race.
The hare can wait the difference then run the remaining 200m in 200/8 seconds. The tortoise goes x in that time.
x/.2 = 200/8

V=at
The total change in V is 22+25
The time is 3.5 somethings. I don't think is is seconds. Solve for a.

Can you kindly walk me through the hare problem again? How did you get the 200 m? :D.... Thanks...
 
The hare runs at its max speed of 8.00 m/s toward the goal for 0.800 km
.800 km = 800 m and 1 km = 1000 m so he has 200 m to go.
 
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