PHYSICS
An airplane accelerates down a runway at 3.20 m/s2 for 32.8 s until is finally lifts off the ground. Determine the distance traveled before takeoff.
Answer: d = 1720 m
Which of the following environmental conditions does not affect the activity of enzymes?
The amount of free energy in the cell
The correct formula for aluminum nitrate is
Al(NO3)3
What describes the depletion of a renewable resource?
intensive cultivation of farmland that exhausts soil nutrients
A car starts from rest and accelerates uniformly over a time of 5.21 seconds for a distance of 110 m. Determine the acceleration of the car.
Answer: a = 8.10 m/s/s
Some enzymes require an effector in order to conform to a substrate. The site to which the effector binds is the:
Allosteric site
Given the balanced equation: 2H2(g) + O2(g) --> 2H2O(l)
How many grams of H2O are formed if 9.00 mol H2(g) reacts completely with an excess of O2(g)?
The molar mass of H2O is 18.0g/mol.
162g
which country is most likely to have either a stabilized or a slowly growing population?
Canada
An object is thrown with a fixed initial speed v0 at various angles α relative to the horizon. At some constant height h above the launch point the speed v of the object is measured as a function of the initial angle α. Which of the following best describes the dependence of v on α? (Assume that the height h is achieved, and assume that there is no air resistance.)
v will remain constant, independent of α.
During which phase of the cell cycle does DNA replication occur?
S phase
Which element has exactly five electrons in the highest principal energy level (the outer shell)?
Phosphorus
What is the term for the forces that alter the balance of the subsystems? (ex. Hydrosphere, lithosphere, etc.)
Forcings
A solid conducting sphere is given a positive charge Q. How is the charge Q distributed in or on the sphere?
It is uniformly distributed on the surface of the sphere only
Organisms that reproduce sexually exhibit zygotic, gametic, or sporic meiosis. One way to determine the type of life cycle an organism has is by
comparing the diploid and haploid forms of the organism.
Which of the following must be true for a sample of supercritical uranium (235U)?
A. The density exceeds that found at ambient temperatures and pressures.
B. There is less density than found at ambient temperatures and pressures.
C. The rate of production of neutrons exceeds their rate of consumption.
D. The sample is pure.
C. The rate of production of neutrons exceeds their rate of consumption.
Name three influential forcings.
Solar energy, volcanoes, and greenhouse gases
Two blocks of masses M and m, with M > m, are connected by a light string. The string passes over a frictionless pulley of negligible mass so that the blocks hang vertically. The blocks are then released from rest. What is the acceleration of the block of mass M?
(M-m/M+m) (g)
Which of the following models best depicts how the genetic information in a retrovirus is eventually translated into proteins?
A. RNA in the retrovirus → DNA in the host cell → RNA in the host cell → Proteins
B. DNA in the retrovirus → RNA in the host cell → Proteins
C. RNA in the retrovirus → mRNA in the host cell → Proteins
A. RNA in the retrovirus → DNA in the host cell → RNA in the host cell → Proteins
Ammonium chloride (NH4_44Cl) is dissolved in water, where it undergoes the following dissociation and subsequent reactions:
NH4Cl→NH4++Cl−\text{NH}_4\text{Cl} \rightarrow \text{NH}_4^+ + \text{Cl}^-NH4Cl→NH4++Cl−
In water, ammonium ions (NH4+\text{NH}_4^+NH4+) act as an acid and can further react as follows:
NH4++H2O⇌NH3+H3O+\text{NH}_4^+ + \text{H}_2\text{O} \rightleftharpoons \text{NH}_3 + \text{H}_3\text{O}^+NH4++H2O⇌NH3+H3O+
Given this information, answer the following question:
Which of the following changes will increase the pH of the solution?
A. Adding more NH4Cl to the solution
B. Adding a strong base, such as NaOH, to the solution
C. Increasing the temperature of the solution
D. Adding a strong acid, such as HCl, to the solution
B. Adding a strong base, such as NaOH, to the solution
A forest in a temperate region has been recently cleared due to a wildfire. Over time, various plant and animal species begin to recolonize the area. This process is best described as?
Secondary succession, where the existing soil and seed bank promote rapid regrowth.