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.