A football quarterback runs 15.0 m straight down the playing field in 2.50 s.
He is then hit and pushed 3.00 m straight backward in 1.75 s.
An object that is thrown straight up falls back to Earth. Is it more likely to dislodge the coconut on the way up or down? If air resistance were not negligible, how would its speed upon return compare with its initial speed?
Neglecting air resistance, how does the speed of the rock when it hits the coconut on the way down compare with what it would have been if it had hit the coconut on the way up? If an object is thrown straight up and air resistance is negligible, then its speed when it returns to the starting point is the same as when it was released.
(c) average speed = \(\displaystyle 3.20 km/h,\bar=0\). The speed of propagation of the action potential (an electrical signal) in a nerve cell depends (inversely) on the diameter of the axon (nerve fiber).
If the nerve cell connecting the spinal cord to your feet is 1.1 m long, and the nerve impulse speed is 18 m/s, how long does it take for the nerve signal to travel this distance? Conversations ith astronauts on the lunar surface were characterized by a kind of echo in which the earthbound person’s voice was so loud in the astronaut’s space helmet that it was picked up by the astronaut’s microphone and transmitted back to Earth. Given this information, is acceleration a vector or a scalar quantity? (b) What is its average velocity over a period of one year? A weather forecast states that the temperature is predicted to be \(\displaystyle −5ºC\) the following day. (a) Calculate Earth’s average speed relative to the Sun.Assuming this to be a constant rate, how many years will pass before the radius of the Moon’s orbit increases by \(\displaystyle 3.84×10^6m\)(1%)? A student drove to the university from her home and noted that the odometer reading of her car increased by 12.0 km. (c) If she returned home by the same path 7 h 30 min after she left, what were her average speed and velocity for the entire trip?Solution (a) \(\displaystyle 40.0 km/h\) (b) 34.3 km/h, \(\displaystyle 25º\) \(\displaystyle S\) of \(\displaystyle E\).Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Give an example in which there are clear distinctions among distance traveled, displacement, and magnitude of displacement. Solution (a) \(\displaystyle 3.0×10^4m/s\) (b) 0 m/s 34. Give an example that illustrates the difference between these two quantities. Does a car’s odometer measure position or displacement? Under what circumstances are these two quantities the same? How are instantaneous velocity and instantaneous speed related to one another? (b) The magnitude of the displacement from start to finish (c) The displacement from start to finish 33. Give an example (but not one from the text) of a device used to measure time and identify what change in that device indicates a change in time. There is a distinction between average speed and the magnitude of average velocity. If you divide the total distance traveled on a car trip (as determined by the odometer) by the time for the trip, are you calculating the average speed or the magnitude of the average velocity? Is it possible for speed to be constant while acceleration is not zero? Find the following for path D: (a) The distance traveled.Students achieve the highest accuracies on graphical questions in which they must compare two positive slopes, and they achieve the lowest accuracies on questions in which they must determine or compare a negative slope.We find that students have more difficulties with the intercept in mathematics and with the slope in kinematics.