An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of
the train. When the engineer first sees the
car, the locomotive is 260 m from the crossing
and its speed is 26 m/s.
If the engineer’s reaction time is 0.51 s,
what should be the magnitude of the minimum deceleration to avoid an accident?
Answer in units of m/s
2

If jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, is being done.

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.

7. see worksheet 1 for values of variables x1, x2 and x3 and answer the following questions: a. for each variable find the mean, median, coefficient of skewness, range and population standard deviation. b. compared to variable x1, how are the mean and median affected by extreme values (outliers) seen in x2 and x3. c. is the median or mean the better measure of location for x2 and x3? explain. d. explain the differences in the magnitudes of the skewness coefficients for the three variables. e. what is the relationship between the range and standard deviation looking across the three variables?