Posts by perry
Total # Posts: 47
A map has a scale of 5 cm: 12km. If two cities are 17 cm apart on the map, what is the actual distance between the cities, to the nearest tenth of the kilometer? My answer was 70.8 km
January 28, 2017
4. Read the following paragraph. Then answer the question that follows it. Next, with your right hand, make the wide part of the right end into a loop, holding the two narrow parts between your thumb and your index finger. Take the left end with your left hand, put...
April 1, 2015
cystic fibrosis is caused by a recessive allele. A child has cystic fibrosis, even though neither of his parents has cystic fibrosis. If this couple has another child, what is the probability he or she will NOT have cystic fibrosis ?
November 17, 2014
A jet plane is flying with a constant speed along a straight line, at an angle of 26.5° above the horizontal, as Figure 4.30a indicates. The plane has weight whose magnitude is 86500 N, and its engines provide a forward thrust of 103000 N. In addition, the lift force (...
October 25, 2012
Part a of the drawing shows a bucket of water suspended from the pulley of a well; the tension in the rope is 107.5 N. Part b shows the same bucket of water being pulled up from the well at a constant velocity. What is the tension in the rope in part b?
October 25, 2012
A small block with mass 0.0400 kg slides in a vertical circle of radius 0.0700 m on the inside of a circular track. There is no friction between the track and the block. At the bottom of the block's path, the normal force the track exerts on the block has magnitude 3.85 N...
June 4, 2012
Bromine consists of two major isotopes with the following percent abundances and atomic masses: 79Br (50.54% and 78.918 amu) and 81Br (49.46% and 80.916 amu). Calculate the average atomic mass of bromine.
December 12, 2011
The chemical substance in natural gas is a compound called methane. Its molecules are composed of carbon and hydrogen and each molecule contains four atoms of hydrogen and one atom of carbon. In this compound, 0.33597g of hydrogen is combined with 1g of C12. Use this ...
August 23, 2011
a ball is thrown upward with an initial velocity of 38.9 m/s from the edge of a cliff of height H. The ball lands on the ground at the base of the cliff 12.8 s after it is thrown.
October 31, 2010
AP Physics (circular motion)
The moon revolves about the Earth in a trajectory that is very nearly a circle of radius r = 384,401 km, and requires 27.3 days (23.4 x 10^5 seconds) to make a complete revolution. What is the acceleration of the moon toward the Earth?
September 24, 2009
An open box is made from a square piece of material 36 inches on a side by cutting equal squares from the corners and turning up the sides. Use your calculator to find the maximum volume this box can hold. I got the equation 4x^3-36x^2+1296x = V But when I put it in the ...
September 18, 2009
The question is a child slides down a slide with a 28 degree incline and at the bottom her speed is precisely half what it would have been if the slide had been frictionless. Calculate the coefficient of the kinetic friction between the slide and the child.
September 18, 2009
A stunt driver wants to make his car jump over eight cars parked side by side below a horizontal ramp. (a) With what minimum speed must he drive off the horizontal ramp? The vertical height of the ramp is 1.5m above the cars, and the horizontal distance he must clear is 20m. (...
September 14, 2009
When you are running and want to stop quickly, you must decelerate quickly. What is the origin of the force that causes you to stop? Estimate the maximum rate of deceleration of a person running at top speed to come to rest.
September 11, 2009
In archery, should the arrow be aimed directly at the target? How should your angle of aim depend on the distance to the target? I know the answer is no but I don't know how to prove that.
September 2, 2009
A runner hopes to complete the 10,000m run in less than 30 minutes. After exactly 27 minutes, there are still 1100m to go. The runner must then accelerate at 0.20 m/s^2 for how many seconds in order to achieve the desired time?
August 30, 2009
Hello! I have a question that leaving me stumped. So E means opposite and Z means together. In order to do this alternate cis/trans arrangement you have to order molecules a priority either 1 and 2. You have to go along either side of double bond and determine priority. I'...
July 3, 2009
HI, could anyone help with this please. :) 2. Find the following values: a) An intial $500 compounded for 10 years at 6 percent b) An intial $500 compounded for 10 years at 12 percent c) The present value of $500 due in 10 years at a 6 % discount rate. d) The present value of...
November 3, 2007
Hi, would anyone be willing to help with this. Thanks :) 2. Find the following values: a) An intial $500 compounded for 10 years at 6 percent b) An intial $500 compounded for 10 years at 12 percent c) The present value of $500 due in 10 years at a 6 % discount rate. d) The ...
November 3, 2007