11) A racing car accelerates uniformly from rest along a straight track. This tr

Question

11) A racing car accelerates uniformly from rest along a straight track. This track has markers spaced at equal distances along it from the start, as shown in the figure. The car reaches a speed of 140 km/h as it passes marker 2. speed 0 speed 140 kmh Start Marker l Marker 2 Where on the track was the car when it was traveling at half this speed, that is at 70 km/h? A) Before marker 1 B) At marker 1 C) Between marker I and marker 2 12) A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct? A) On the way up, its acceleration is downward and its velocity is upward, and at the highest point both its velocity and acceleration are zero B) On the way down, both its velocity and acceleration are downward, and at the highest point both its velocity and acceleration are zero. C) Throughout the motion, the acceleration is downward, and the velocity is always in the same direction as the acceleration. D) The acceleration is downward at all points in the motion E) The acceleration is downward at all points in the motion except that is zero at the highest 3) Suppose a ball is thrown straight up and experiences no appreciable air resistance. What is its acceleration just before it reaches its highest point? C) exactly g D) slightly grcater than g B) slightly less than g 14) A 10-kg rock and a 20.-kg rock are thrown upward with the same initial speed vo and experience no significant air resistance. If the 10-kg rock reaches a maximum height h, what A) h4 B) h'2 D) 2h 15) A 10-kg rock and 20-kg rock are dropped from the same height and experience no significant air resistance. If it takes the 20-kg rock a time T to reach the ground, what time will it take the 10-kg rock to reach the ground? A) 47 B) 27 C) T D) T72 E) T4 16) From the edge of a roof top you toss a green ball upwards with initial speed vo and a blue ball downwards with the same initial speed. Air resistance is negligible. When they reach the ground below A) the green ball will be moving faster than the blue ball. B) the blue ball will be moving faster than the green ball. C) the two balls will have the same speed Copyright © 2014 Pearson Education, Inc

Explanation / Answer

11) A) Before Marker 1;

12) D) Acceleration is always downward

13) C) Exactly g

14) C) h

15) C) T

16) C) The both balls will have the same speed

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.