Emily challenges her husband, David, to catch a $1 bill as follows. She holds the bill vertically as in Figure P2.69, with the center of the bill between David’s index finger and thumb. David must catch the bill after Emily releases it without moving his hand downward. If his reaction time is 0.2 s, will he succeed? Explain your reasoning. (This challenge is a good trick you might want to try with your friends.)

What is E and F?? Please help!

A swimmer bounces straight up from a diving board and falls feet first into a pool. She starts with a velocity of 4.0 m/s, and her takeoff point is 1.1 m above the pool.  Which of these two valid methods is the easiest to find how long her feet are in the air? Group of answer choices Break the problem in two parts. For part 1, find the time to reach her highest point by using v0 = 4 m/s, a = -9.8 m/s2, and vf = 0 m/s.  For part 2, you can use the highest point above the board found in the previous problem and add it to her height above the pool. Then, using v0 = 0 m/s and a = -9.8 m/s2, you can find the time to reach the ground. Since you only care about the end points in this case, you can use v0 = 4 m/s, a = -9.8 m/s2, and Δy = -1.1 m to find the time to reach the ground.

You’re trying to find your classroom in the labyrinth that is Gilman Hall, walking through the halls at an average pace of 1.4 m/s. You look up from your phone displaying the room number to see that a group of students is suddenly standing in the middle of the hallway 1.8 meters away! How much time (in seconds) do you have to react before you bump into them

At a soccer practice, the players run sprints. They start at the goal, run 10 m toward the center of the field and then run back to the goal. Then they run 20 m toward the center of the field and back to the goal. Finally they run 30 m toward the center of the field, turn around, and run back to the goal again. One player times herself to try and beat her personal best time. She runs the first 10 m in 2.5 s and gets back to the goal in 2.8 s. Then she runs the 20-m sprint in 5.7 s and gets back to the goal in 6.7 s. She runs the final 30-m sprint in 12 s and gets back to the goal in 15 s. Define the positive direction as forward, toward the center of the field and consider what a position versus time graph of her motion would look like. Rank the sprints according to their slopes on the position versus time graph, from steepest positive slope to steepest negative slope. Rank from steepest positive slope to steepest negative slope. To rank items as equivalent, overlap them.

The position of a dragonfly that is flying parallel to the ground is given as a function of time by 7 = [2.90 m + (0.0900 m/s²)t²] i – (0.0150 m/s³)t³ j. Part B At the time calculated in part (a), what is the magnitude of the acceleration vector of the insect? Express your answer with the appropriate units. xa μÅ Xb a = 0.062 a b X.10n m Submit Previous Answers Request Answer ?

4. A robotic vehicle is exploring the surface of Mars. The robot, which is represented as a point, has x - and y-coordinates that vary with time: x = (3 − 2t); y = (-t² + 4t³) where x and y are in meters and t is in seconds. a. Find the average velocity of the robot between t = 0s and t = 2s. b. Find the average acceleration of the robot between t = 0s and t = 2s. c. At what time the acceleration of the robot will be zero. a. Vavg= -21 + 14ĵ m/s b. davg = 22ĵ C. m s² 2 t = = = 0.083 s 24

I think I have it, but I need a second opinion.

A group of students in a science class monitored the movement of a cat walking along with a straight line and recorded the cat's position in five-second intervals.The results are summarized it in the table below.  time and position time(s) position (cm) 0 49.0 5 38.0 10 43.0 15 40.0 20 60.0   A. What is the displacement of the cat between t = 5.00 s and t = 20.0 s?   B. What is the average velocity of the cat between t = 5.00 s and t = 20.0 s?   C.What is the distance the cat traveled between t = 5.00 s and t = 20.0 s?

At t=0 an object has a velocity of 35 m/s and a steady acceleration of -10 m/s2.   Make a sketch of velocity vs. time for this motion from t=0 to t=5 s. Make a sketch of acceleration vs. time for this motion from t=0 to t=5 s. Does the object change directions between 0 and 6 s?