Recent content by fightboy

Genes A/a and B/b are linked and known to be 20 map units apart. Individuals heterozygous for both of these genes (genotypes= AB/ab) were mated with each other. If there 2000 offspring from this cross, how many of the offspring would you expect to show Ab or aB phenotypes? I know that the...

Homework Statement A large, uniform-density cube of styrofoam has a side length of 3.0 m and a mass of 90 kg. It is at rest on a horizontal, frictionless (ice) surface. An ice-skater with a mass of 60 kg is standing at rest, touching one face of the cube. You should consider all of the...

ah ok i forget to apply the conservation of energy equations to this problem, I'll give it a go thanks!

A 400kg roller coaster cart travels along the inside of a vertical circular track of radius 10 m. At its highest point it moves at 20 m/s. Friction between the cart and track is negligible. Find the cart's speed one quarter of a loop later (when it's at the same height as the loop's center). I...

Thank you guys very much! The graph really helped once I divided the area in different shapes.

Yes the total distance would be 1 km. but I don't know how to divide the distances evenly between the time he accelerated and the time he remained at constant speed till the end of the race.

yes since wouldn't that help me find out what the acceleration is? and ok i did that but i still don't get it:(. All i have on my graph after 9 km is an upward line for the first 60 seconds he accelerated, and then a horizontal line to show that he traveled for the duration at constant speed.

I did that but since his speed is unknown after the 9 km mark, i can't really draw anything after that point

In April 1974, Steve Prefontaine completed a 10.0-km race in a time of 27 min, 43.6 s. Suppose “Pre” was at the 9.00-km mark at a time of 25.0 min even. If he accelerates for 60.0 s and maintains the increased speed for the duration of the race, calculate the acceleration that he had. Assume his...

https://www.physicsforums.com/attachments/74483 https://www.physicsforums.com/attachments/74483 Based in the absorption spectra above, why is 595 nm the best wavelength to measure protein concentration with Bradford dye (Hint: there are two important reasons for choosing 595). I think it has...

When water freezes into ice it expands in volume by 9.05 percent. Suppose a volume of water is in a household water pipe or a cavity in a rock. If the water freezes, what pressure must be exerted on it to keep its volume from expanding? (If the pipe or rock cannot supply this pressure, the pipe...

A cylindrical steel rod is originally 250 cm long and has a diameter of 0.254 cm. A force is applied longitudinally and the rod stretches 0.85 cm. What is the magnitude of the force? The value for Young's Modulus for steel is 200*109 Pa. The correct answer is 3400 N, i used the equation...

Ok so for this example you have to calculate the net torque about an axis that passes through the hinges in each of the following cases in the image: a) and c) were fairly straightforward to calculate but i had issues with b) and c). The solution listed the angle for b) as sin(115°) and for...

The numerator is ##\frac{2}{5}m_ER_E^2##. I get that ##\frac{2}{5}m_ER_E^2##/##\frac{2}{5}m_ER_E^2## is equal to 1, I am mainly confused on how (2/3mdebrisRE2) became (5/3mdebris) or if the manual made a mistake.

Ok so for the problem I'm mainly having trouble with setting up one of the equations. The solutions manual jumped from: ωiz([(2/5mERE2)/(2/5mERE2) + (2/3mdebrisRE2)]-1) to: ωiz([mE/(mE + (5/3mdebris))]-1) I placed the brackets to clearly separate the fraction from the -1. Anyways I'm...