Please help me solve these questions: Chapter 2 (2,6,7) Chapter 3 (1,2) Chapter
ID: 1873667 • Letter: P
Question
Please help me solve these questions: Chapter 2 (2,6,7) Chapter 3 (1,2) Chapter 4 (1,3,5) Chapter 5 (3,5,8,9) of the attached documents. Thanks
Chapter 2: Motion Along a Straight Line 1. A car moves at a speed of 30m/s when suddenly the driver brakes the car at 12m/s2. How far will the car travel until it stops? How long will it take the car to stop? 2. An Olympic sprinter can run the 100m dash in 10s. What must the acceleration of the sprinter be during this run, if we assume that the acceleration is costant? What is the final speed of the sprinter when he or she crosses the finish line? 3. A car accelerates from rest at 10/s2 for 5s, then brakes at a rate of 15m/s2 untit stops again. How far does the car travel during this motion? Graph the car's position vs. time and velocity vs. time during this motion 4. An object is dropped from the top of a building and is observed to take 5s to hit the ground How tall is the building? 5. You want to toss an object from the ground up to your friend on a second-story balcouy If your friend is about 4m above you, what minmum ntial speed do you have to throw the object up with for it to reach your friend? Assume that you throw the object straight upwards. 6. A car is speeding, doing 40m/s in a 35m/s zone, when it passes by a police car. If the police car is at rest, but accelerates at 10m/s2, how long will it take for the police car to catch up to the speeding car? How far will they both travel during this timel? 7. An object has a position at any time t given by the following function: 2(1) = a13 + bl-c where 10m/s3, b-5m/s, and c = 6m. What is the velocity of the object at any time t? What is the acceleration of the object at any time t? Could you use kinematics to study the object's motion? 8. An object has a velocity at any time t given by the following equation where a is some constant. What would the object's acceleration be at any time t? What would the object's displacement be from 0 to any time t? 9. An object moves with a position at any time t given by the function: r(t) (2m/s)t - (13m/s2)t2+4m At what time will the object be at rest? Does this object move with a constant or non-constant acceleration? Could y use kinematics to study the motion of this object?Explanation / Answer
Chapter2
2)
Displacement D = 100m
time t = 10s
Use the kinematic eqn:
S = 1/2*at2
=> a = 2S/t2
= (2*100)/102
= 2 m/s2
For the final speed, use the kinematic eqn:
v = at
= (2) (10)
= 20 m/s