Nov 30 2:29 PM

Super job on the final everyone! Essay: Bring to class on Monday with the rubric scored and the essay underlined everywhere you got a point. For those of you that have still to do the essay I will place it here for you to read and make sure you answered all the parts. A person has a bow that takes 500N to fully pull back. They have put in the string a 0.1 kg arrow. Define Newton's three laws in terms of the person shooting an arrow. Describe what happens, and why it happens for each of Newton's three laws and the forces of friction ( and any other forces on the arrow). Describe what happens to pull back the string, and the result as you let it go. Also describe what could be done or forces on the arrow that would make the same shot go in three different locations other than the target they aim for. Each idea gets a paragraph,,,example: define Newton's first law...... it applies to the bow and arrow because... The arrow if shot over a target would...because.... define Newtons second law... it applies to the bow and arrow because... The arrow is shot with more _____ then._______...because or if the arrow was twice the mass then...because... define Newtons third law... it applies to the bow and arrow because... The force on the string is on the hand of the archer, and the force........because or the arrow would not go as far if the force...... then...because Also read 'The law of Conservation' on the Physics Classroom web page we looked at today in class. We will learn to do problems on Monday.

problem set

You must finish all the problems, as many of you did not do most of the problems.

nov 20

1. A force of 20 N acts upon a 5 kg block. Calculate the acceleration of the object. 2. An object of mass 300 kg is observed to accelerate at the rate of 4 m/s2. Calculate the force required to produce this acceleration. 3. A 5 kg block is pulled across a table by a horizontal force of 40 N with a frictional force of 8 N opposing the motion. Calculate the acceleration of the object. 4. An object of mass 30 kg is in free fall in a vacuum where there is no air resistance. Determine the acceleration of the object. 5. An object of mass 30 kg is falling in air and experiences a force due to air resistance of 50 newtons. a. Determine the net force acting on the object by doing a free-body diagram with vectors….and b. calculate the acceleration of the object. 6. A student pushes on a crate with a force of 200 N directed to the right. What force does the crate exert on the student? 7. A force of 100 N is exerted on an object of mass 40 kg that is located on a sheet of perfectly smooth ice. a. Calculate the acceleration of the object. b. If a second object identical to the first object is placed on top of the first object, what acceleration would the 100 N force produce? 8. Just before opening her parachute a skydiver of mass 50 kg reaches terminal velocity. Calculate the force of air resistance. This means they go a constant velocity and acceleration is zero. 9. For a person who has a mass 60 kg, calculate the weight in Newtons and in pounds (find a conversion app).. 10. An object of mass 10 kg is accelerated upward at 3 m/s2. What force is required? If you have problems answering questions, call a friend to discuss it.

nov 14

Be ready to finish your presentations to Mr. Hennessy. If you already went, then you did a great job, but take notes on the posted presentations.

Thurs HW

Read the information at: http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html search two other web sites for Newton's three laws of motion. Come up with extensive definitions for these three laws and memorize them.

Nov 7th

A person throws a ball downwards into the Grand Canyon at an initial speed of 10 m/s. What is the final speed of the ball after 20 seconds? How far would it travel in 20 seconds? If the canyon is 1600 meters deep at that spot, will it hit the ground before the 20 seconds are even up? If you throw a ball up into the air with an initial velocity of 20 m/s, how long will it take until it reaches its highest point? Remember that the acceleration of the ball is now negative because it is pulling the ball down as you throw it up, therefore decreasing its speed every second. Also know at its highest point the ball has a velocity of 0 m/s. A car going down the highway at a constant acceleration of 3.2 m/s2 , travels for 15 seconds. What is the final speed, and what is the distance it travels during that period? Do the questions out in the five step format on a piece of paper and hand it in at the begging of class. If you still don't know how to do these questions, research them online.

Nov 5 homework

A person throws a ball downwards into the Grand Canyon at an initial speed of 10 m/s. What is the final speed of the ball after 10 seconds? How far would it travel in 10 seconds? If the canyon is 1600 meters deep at that spot, will it hit the ground before the 10 seconds are even up? If you throw a ball up into the air with an initial velocity of 10 m/s, how long will it take until it reaches its highest point? Remember that the acceleration of the ball is now negative because it is pulling the ball down as you throw it up, therefore decreasing its speed every second. Also know at its highest point the ball has a velocity of 0 m/s. Do the two questions out in the five step format on a piece of paper and hand it in at the begging of class. If you still don't know how to do these questions, research them online.

Nov 5

Read about falling objects in the student resources.

nov 1

We will continue with the test for half an hour of the period. If you are not done by then, plan on staying awhile to finish after school.