Potential Energy-- activity's problems

Here are the problems you were supposed to finish in class. Make sure to finish them.

a)    *Legend has it that Isaac Newton “discovered” gravity when an apple fell from a tree and hit him on the head. If a 0.20 kg apple fell 7.0 m before hitting Newton, what was its change in PE during the fall?

b)    *It is said that Galileo dropped objects off the Leaning Tower of Pisa to determine whether heavy or light objects fall faster. If Galileo had dropped a 5.0 kg cannon ball to the ground form a height of 12 m, what would have been the change in PE of the cannon ball?

c)    *A 0.80 kg bird, perched on a power line 6.0 m above the ground, swoops down to snatch a worm form the ground and then returns to an 8.0 m high tree branch with his catch. By how much did the bird’s PE increase in its trip from the power line to the tree branch?

d)    *A Mexican jumping bean jumps with the aid of a small worm that lives inside the bean. If a bean of mass 2.0 g jumps 2.5 cm from your hand into the air, how much potential energy has it gained in reaching its highest point?

FOR GEOGRAPHY 7TH GRADE STUDENTS!!!!!

These are the instructions you need to follow to earn the 10 bonus points. Make sure to follow them correctly!

Use the map given to you, or print the one above, to do the following:

•Use a red color to outline the United States.

•Use a blue color to outline Canada.

•Put a Yellow star where the Capital City of each country is. Label the Capital Cities.

•Write the name of 20 of the states in the United States.

•Write the name of the 10 provinces and 3 terrotories in Canada.

•Write the names of the oceans these countries border with.

•Identify and label the 3 largest cities in US with an orange dot.

•Identify the capital city of 5 provinces in Canada with a black dot.

•Write, next of each country, the year of its independence.

Elastic and Inelastic Collisions.- Homework due on Monday, February 14th

This homework must be handed-in on block paper before 8:00 am on the due date. Problems must be copied and all process must be shown. The final answer must be in a red rectangle. Any instruction not will cause a lower grade.

1. Miguel, the 72.0 kg bullfighter, runs toward an angry bull at a speed of 4.00 m/s. The 550 kg bull charges toward Miguel at 12.0 m/s and miguel must jump on the bull's back at the last minute to avoid being runover.
a) What kind of collision is this?
b) What is the new velocity of Miguel and the bull as the move across the arena?

2. Charlotte, a 65.0 kg skin diver, shoots a 2.0 kg spear with a speed fo 15 m/s at a fish who darts quickly away without getting hit. How fats does Charlotte move backwards when the spear is shot?

3.Jeanne rolls a 7.0 kg bowling ball down the alley for the league championship. One pin is still standing, and Jeanne hits it head-on with a velocity of 9.0 m/s. The 2.0 kg pin acquires a forward velocity of 14.0 m/s.
a) What kind of collision is this?
b) What is the new velocity of the ball?

4. To test the strength of a retainment wall designed to protect a nuclear reactor, a jet aircraft was crashed head-on into a concrete barrier at high speed. The jet aircraft had a mas of 19100 kg, while the retainment wall's mass was 469000 kig. The wall sat on a cushion of air that allowed it to move during impact. If the wall and the aircraft moved together at 8.41 m/s during the collision,
a) what was the initial speed of the aircraft?
b) What kind of collision is this?

5. A 620.0 kg moose stands in the middle of the railroad tracks, frozen by the lights of an oncoming 10000 kg locomotive that is traveling at 10.0 m/s. The engineer sees  the moose but is unable to stop the train in time and the moose rides down the track sitting on the cowcatcher.
a) What kind of collision is this?
b) What is the new combined velocity of the locomotive and the moose?

MOMENTUM.- Homework due Wednesday February 9, 2011 (for 8th A and 8th C only)

Solve the following problems on your notebook. Copy the problems and show all your process, hand in your notebook before 8:00 am.

1.    On April 15,1912, the Luxury cruiseliner Titanic sank after running into an iceberg. What momentum would the 4.23 x 10⁸ kg ship have imparted the iceberg if it had hit the iceberg head-on with a speed of 11.6 m/s?

2.    Auto companies frequently test the safety of automobiles by putting them through crash tests to observe the integrity of the passenger compartment. If a 1000 kg car is sent toward a cement wall with a speed of 14 m/s and the impact brings it to a stop in 0.08 s, with what average force is it bought to rest?

3.    Rhonda, who has a mass of 60.0 kg, is riding at 25 m/s in her sports car when she must suddenly slam on the brakes to avoid hitting a dog crossing the road. She is wearing a seatbelt, which brings her body to stop in 0.400 s,

a)    What average force did the seatbelt exert on her?

b)    If she had not been wearing her seatbelt, and the windshield had stopped her head in 0.001 s, what average force would the windshield have exerted on her?