A radioactive isotope has a half-life of 13 hours. Find the amount of the isotope left from a 400 -milligram sample after 52 hours. If necessary, round your answer to the nearest thousandth. 12.5 mg 25 mg 7.692 mg 0.049 mg
How does Bohr's model overcome the issue of radiation from accelerating electrons? By allowing only certain orbits where no radiation occurs By assuming electrons are massless By using a relativistic speed correction By eliminating the concept of electron movement
The first law of thermodynamics and the law of conservation of matter are similar in that __ both energy and matter are recycled through biological systems. both energy and matter flow in a one-way path through biological systems. under normal circumstances energy and matter are destroyed as they pass through biological systems. under normal circumstances neither energy nor matter is created nor destroyed. The first law of thermodynamics and the law of conservation of matter are not similar.
What is true of using the scientific method in astronomy? The first step of the scientific method is collecting information by using tools such as telescopes and spaceships. We don't use the scientific method in astronomy because we can't do the experiment phase. It gives us a good guess of what is going on in the cosmos but isn't backed by evidence. We can't make any conclusions based on the evidence we have collected from space exploration.
014 100 points Find the total translational kinetic energy of 3 L of oxygen gas held at a temperature of 9^circ C and a pressure of 0.5 atm.
A certain substance has a half-life of 8 weeks. How many grams of a 10 -gram sample will be remaining after 2 weeks? Round to 2 decimal places. Answer square
What happens to matter when energy changes?
Which force is always attractive and has a very small range? strong nuclear weak nuclear gravitational electromagnetic
The energy of microwaves is less than the energy of ultraviolet light.Which comparison of the energies of electromagnetic waves is correct? X-rays have lower energy than gamma rays because X-rays have higher frequencies. X-rays have lower energy than gamma rays because X-rays have shorter wavelengths. Visible light has higher energy than infrared light because visible light has longer wavelengths. Visible light has higher energy than infrared light because visible light has higher frequencies.
Which are characteristics of electromagnetic waves?Check all that apply. They travel only through matter. Waves with a higher frequency have a shorter wavelength. ) Waves with a higher frequency have a longer wavelength. They all move at the same speed. They can travel through space.
A heavy stone and a light stone are released from rest in such a way that they both have the same amount of gravitational potential energy just as they are released. Air resistance is negligibly small Which of the following statements about these stones are correct? (There could be more than one correct choice.) a) The stones must have been released from the same height. b) Just as it reaches the ground, the light stone is traveling faster than the heavy stone. c) The initial height of the light stone is greater than the initial height of the heavy stone. d) The stones both have the same speed just as they reach the ground. e) The stones both have the same kinetic energy just as they reach the ground.
33. What does a transformer do? 34. Write the transformer equation relating voltage and number of turns. 35. A transformer has 200 turns in the primary coil and 20 in the secondary coil If the input voltage is 2400 V.what is the output voltage? 36. Why is voltage stepped up for power transmission over long distances?
Calculate the force on a 160m wire carrying 150A of current if a magnetic field of $5\times 10^{-5}$ T makes a $165^{\circ }$ angle with the wire. $\square $ N
Two iron bars attract each other no matter which ends are placed together. Are they both magnets? Explain. $\square $
Absolute vorticity is a combination of curvature and shear vorticity. True False
A gravitational field surrounds anything that has __ A density B electricity C velocity D mass
You would have the largest mass of gold if it weighed 1 N on the Moon Earth both the same on the Earth the mass will be double
How many significant figures are in this length? .002500 dm $\square $
A projectile travels 1,120 feet per second. How fast is the projectile traveling in miles per hour? The projectile travels $\square $ miles per hour. (Type an integer or decimal rounded to the nearest tenth as needed )
Use the formula $F=G\frac {m_{1}m_{2}}{d^{2}}$ where $F=the\quad force\quad of\quad gravity$ $G=universal\quad gravitational\quad constant$ $m_{1}$ and $m_{2}=masses\quad of\quad the\quad two\quad objects$ $d=the\quad distance\quad between\quad the\quad centers\quad of\quad the\quad two\quad objects$ What would result in the greatest gravitational force between two objects? A halving the mass of object 1 B doubling the mass of object 1 C halving the distance between the two objects D doubling the distance between the two objects
