At any one time, the dominant naturally occurring radioisotopes in the human body are 14.0 mg of Potassium-40 (half-life 1.25 X 109 years) and 16.5 ng of Carbon-14 (half-life 5730 years). Calculate the body’s natural radioactivity in becquerels (Bq).
In: Physics
1a. Give 6 examples where Energy is Conserved in an event.
1b. Give 6 examples where Energy is NOT Conserved in an
event.
1c. Give 2 examples of an event where Momentum is NOT
Conserved.
In: Physics
given that a large population which has been living on an isolated is in hardy weinberg equilibrium; what can be said about the relative fitness of the dominant individuals relative to the recessive individuals
In: Physics
an Astronomy question, please answer it comprehensively. Thank you
List (and explain) two reasons astronomers suspect that Dark Matter exists.
In: Physics
Question 1
A 242 g box slides up a 16.1° ramp at a speed of 4.05 m/s. Using conservation of energy and assuming the ramp is frictionless, how far along the ramp does the box slide before stopping?
0.745 m
3.02 m
29.6 m
0.871 m
Question 2
A 10800 kg jet is preparing to land on a military aircraft carrier. In order to do so, the pilot manoeuvres the jet's tail to hook and snag a cable that is attached to a spring with spring constant 71200 N/m. If the spring stretches 33.0 m to stop the jet, what was the jet's landing speed?
218 m/s
14.7 m/s
84.7 m/s
120. m/s
Question 3
You are lawn bowling and bowl a ball with a speed of 5.23 m/s. Unfortunately, your ball hits a large rock of mass 310 g, resulting in a perfectly elastic collision. If the final velocity of the ball after the collision is -2.42 m/s, what must the mass of the ball be?
0.114 kg
0.844 kg
0.424 kg
1.18 kg
In: Physics
The sound intensity is 0.0072 W/m2 at a distance of 20 m from an isotropic point source of sound. (a) What is the power of the source? (b) What is the sound intensity 6.1 m from the source? (c) What is the sound level 20 m from the source?
In: Physics
A photon of wavelength 6.63 pm scatters at an angle of 167 ∘ from an initially stationary, unbound electron. What is the de Broglie wavelength of the electron after the photon has been scattered?
In: Physics
An ideal monatomic gas originally at a pressure of 3x105 Pascals and 75 moles and volume 1.2 m3 & Ti is expanded isothermally to a volume of 3.5 m3 at which point it has pressure P1. It then experiences an isovolumic process to a lower pressure P2, T2. Finally, it is compressed adiabatically back to its original state and returns to its original pressure, temperature, and volume.
Find:
Ti , P1 , P2 , T2
ΔE1 of gas, ΔE2 of gas , ΔE3 of gas , ΔETotal of gas
W1by gas, W2 by gas, W3 by gas, WTotal by gas
Q1 into gas, Q2 into gas, Q3 into gas, QTotal into gas
Answers should be:
Ti = 577.62 Kelvin, P1 = 102,857.14 Pascals, P2 = 50,206.54 Pascals, T2 = 281.95 Kelvin
ΔE1 of gas = 0 Joules, ΔE2 of gas = -276.41 kJoules, ΔE3 of gas = 276.41 kJoules, ΔETot of gas = 0 Joules
W1 by gas = 385.36 kJoules, W2 by gas = 0 Joules, W3 by gas = -276.41 kJoules, WTot by gas = 108.95 kJoules
Q1 into gas = 385.36 kJoules, Q2 into gas = -276.41 kJoules, Q3 into gas = 0 Joules, QTot into gas = 108.95 kJoules
In: Physics
A cockroach of mass m lies on the rim of a uniform disk of mass 4.00 m that can rotate freely about its center like a merry-go-round. Initially the cockroach and disk rotate together with an angular velocity of 0.230 rad/s. Then the cockroach walks half way to the center of the disk.
What then is the angular velocity of the cockroach-disk system? What is the ratio K/K0 of the new kinetic energy of the system to its initial kinetic energy? What accounts for the change in the kinetic energy?
In: Physics
How to combine the point-particle and real system/extended system analyses of a system to compute changes in the system’s internal energy?
In: Physics
In: Physics
A uniform disk with mass 8.5 kg and radius 8 m is pivoted at its center about a horizontal, frictionless axle that is stationary. The disk is initially at rest, and then a constant force 31.5N is applied to the rim of the disk. The force direction makes an angle of 35 degrees with the tangent to the rim. What is the magnitude v of the tangential velocity of a point on the rim of the disk after the disk has turned through 8.1 revolutions? The unit of the tangential velocity is m/s.
In: Physics
Consider the following. (a) Find the angle θ locating the first minimum in the Fraunhofer diffraction pattern of a single slit of width 0.186 mm, using light of wavelength 424 nm. (b) Find the angle locating the second minimum.
In: Physics
Problem 3
The purpose of this problem is to find the Net Magnetic Field force of the two electric currents at point P.
There are two parallel wires carrying currents I1 = 15 A and I2 =25 A, as it is shown in the figure below. The arrow on each wire shows the direction of the current in the wire.
The distance between the two wires is 10 Cm. The distance between point P and the wire (I1 ) on the left is 4 Cm.
1 Cm = 10-2 m
Instruction:
Solid blue circle indicates the direction of the electric current is out of the paper
Solid blue circle with a cross sign indicates the direction of the electric current goes in to the paper.
I1 = 15.0 A (solid blue) -------------------pX-------------------------------------------------------(solid blue w/cross) I2 = 25.0
B1 =
B2 =
In: Physics
Three identical stars of mass M form an equilateral triangle that rotates around the triangle’s center as the stars move in a common circle about that center. The triangle has edge length L. What is the speed of the stars? b.) What is the period of revolution? c.) What is the total potential energy of the 3 star system? Express your answers in terms of the star mass M and triangle edge length L. Hint: Draw a diagram showing the gravitational forces on each star. d.) Find the gravitational force on a single star due to the gravitational attraction of the other two stars, (magnitude and direction). Hints: the 2nd law for a single particle orbiting a planet i.e. Fg = M v 2 /R. You will need to express R in terms of the triangle edge length L. Use v T = 2πR to find the period. it is a symbols-only problem. All work must be done in symbols. There are no numbers.
In: Physics