15. a car is driving north at a steady speed. it makes a gradual 90° left - turn without losing speed, then…

15. a car is driving north at a steady speed. it makes a gradual 90° left - turn without losing speed, then continues driving to the west. draw a motion diagram, using the particle model, showing the cars velocity vectors as seen from a helicopter hovering over the highway.\n16. a toy car rolls down a ramp, then across a smooth, horizontal floor. draw a motion diagram, using the particle model, showing the cars velocity vectors.\n17. density is the ratio of an objects mass to its volume. would you expect density to be a vector or a scalar quantity? explain.\nmultiple - choice questions\n18. a student walks 1.0 mi west and then 1.0 mi north. after - ward, how far is she from her starting point? a. 1.0 mi b. 1.4 mi c. 1.6 mi d. 2.0 mi\n19. you throw a rock upward. the rock is moving upward, but it is slowing down. if we define the ground as the origin, the position of the rock is ____ and the velocity of the rock is ____ a. positive, positive b. positive, negative c. negative, positive d. negative, negative\n20. which of the following motions could be described by the motion diagram of figure q1.20? a. a hockey puck sliding across smooth ice. b. a cyclist braking to a stop. c. a sprinter starting a race. d. a ball bouncing off a wall.\n21. which of the following motions is described by the motion diagram of figure q1.21?

15. a car is driving north at a steady speed. it makes a gradual 90° left - turn without losing speed, then continues driving to the west. draw a motion diagram, using the particle model, showing the cars velocity vectors as seen from a helicopter hovering over the highway.\n16. a toy car rolls down a ramp, then across a smooth, horizontal floor. draw a motion diagram, using the particle model, showing the cars velocity vectors.\n17. density is the ratio of an objects mass to its volume. would you expect density to be a vector or a scalar quantity? explain.\nmultiple - choice questions\n18. a student walks 1.0 mi west and then 1.0 mi north. after - ward, how far is she from her starting point? a. 1.0 mi b. 1.4 mi c. 1.6 mi d. 2.0 mi\n19. you throw a rock upward. the rock is moving upward, but it is slowing down. if we define the ground as the origin, the position of the rock is ____ and the velocity of the rock is ____ a. positive, positive b. positive, negative c. negative, positive d. negative, negative\n20. which of the following motions could be described by the motion diagram of figure q1.20? a. a hockey puck sliding across smooth ice. b. a cyclist braking to a stop. c. a sprinter starting a race. d. a ball bouncing off a wall.\n21. which of the following motions is described by the motion diagram of figure q1.21?

Answer

Explanation:

Step1: Analyze question 18

The student's movements form a right - angled triangle. Use the Pythagorean theorem $d = \sqrt{x^{2}+y^{2}}$, where $x = 1.0$ mi and $y = 1.0$ mi. $d=\sqrt{(1.0)^{2}+(1.0)^{2}}=\sqrt{1 + 1}=\sqrt{2}\approx1.4$ mi

Step2: Analyze question 19

The rock is above the ground (origin), so the position is positive. It is moving upward, so the velocity is positive.

Step3: Analyze question 20

In the motion diagram of Figure Q1.20, the dots are getting closer together, indicating a decrease in speed. A cyclist braking to a stop has a decreasing speed.

Step4: Analyze question 21

Since the figure for Q1.21 is not shown completely, we assume based on the general analysis of options. An airplane braking to a stop after landing has a decreasing speed and a motion diagram with dots getting closer together.

Answer:

  1. B. 1.4 mi
  2. A. positive, positive
  3. B. A cyclist braking to a stop
  4. B. An airplane braking to a stop after landing