Quiz postponed

.... Until next week (Tuesday).

HW for Thursday

1.  Consider a car starting from rest.  If it has an acceleration of 4 m/s/s, find the following:

a.  how fast the car is moving after 7 seconds
b.  how far the car has gone in this time

2.  Consider a falling object, subject only to gravity (a = 9.8 m/s/s, with no air resistance).

a.  How fast is a falling ball moving after 3 seconds of freefall?
b.  How far will it have fallen in this time?

3. If a ball is dropped from 15 m, how long does it take to hit the ground?  Assume that the acceleration is due only to gravity and that there is no air resistance.

4.  Consider a baseball pitch, starting from rest and accelerating up to 45 m/s in a 0.5 m pitching arc.  Find:

a.  the acceleration of the ball
b.  the time that the pitcher is in contact with the ball

5.  Try this:  Derive a "5th equation of motion," in which initial velocity (Vi) is absent.

ALSO - WE WILL HAVE A QUIZ IN 2 CLASSES.  Units, unit conversions, speed....

HW for Tuesday

First, some Fermi questions to play with:

1.  How many hairs are on your head?

2.  How many times does one of the tires on a car rotate in its lifetime?

3.  How many toilets are there in all of the major league football stadiums, baseball parks, and basketball arenas in the USA?

Now some motion math.

4.  What is the difference between traveling at an average speed vs. a constant speed (for the same distance)?  In other words, if you were traveling at an average speed of 5 m/s vs. traveling at a constant speed of 5 m/s, would you go a greater distance in either case (after, say, 10 minutes)?  Discuss.

5.  Find the definition of acceleration and write it down.

6.  Consider a car traveling at a constant 10 m/s in a straight line.  What would a graph of distance (or position) vs. time look like for 50 seconds of travel time?  What would a graph of speed vs. time look like for the same time period?

FUN Homework!

Here are some unit problems to play with:

1.  Create a factor to convert from m/s to light-years (LY) per millennium.  1 LY = 9.4607 x 10^12 km.

2.  Create your own conversion factor - m/s to something else interesting.

3.  How long is a micro-century?  Give your answer in units that are appropriate.   Also, micro equals 1 millionth.

4.  How long is a nano-year.  Nano is a billionth.

5.  Roughly, what is the growth rate of your hair in m/s?

6.  What is your average speed on the way to school - in miles per hour (and m/s)?

For fun:

https://en.wikipedia.org/wiki/List_of_humorous_units_of_measurement