According to present scientific understanding of the Milky Way's formation, which of the following statements are true? Select al that apply. Halo stars formed before disk stars. Disk stars formed before halo stars. The galaxy formed from the collapse of a single, giant protogalactic cloud. Halo stars are stars that are born in the disk and ejected into the halo by gravitational encounters. The protogalatic cloud() contained essentially no elements besides hydrogen and helium.

A tension force of 155 N inclined at 15.0^circ above the horizontal is used to pull a 35.0 kg storage crate a distance of 4.10 m on a rough surface. If the crate moves at a constant speed, find (a) the work done by the tension force and (b)the coefficient of kinetic friction between the crate and surface. HINT (a) the work done by the tension force (in J) square J (b) the coefficient of kinetic friction between the crate and surface square

A transition in the Bohr hydrogen atom from n=4 to n=2 occurs in the __ region of the electromagnetic spectrum. microwave visible infrared X-ray ultraviolet

To say that something is twice as hot as another suggests the ......................................................................the thermal energy. True False

An Earth satellite is simply a projectile freely falling around the Earth. True False

Question 4 of 10 A cat falls from a table of height 13 m. What is the impact speed of the cat? A. 5.0m/s B. 2.5m/s C. 25.5m/s D. 7.5m/s

Water pressure in a lake is __ View Available Hint(s) the same at any point greater at the surface greater at the bottom greater midway to the bottom

8) Hydroplaning occurs when: a) The tires ride up on a film of water b) The front tires lose traction and "push"out through a turn c) Your windshield becomes temporarily blocked by water thrown up by a truck's tires d) You engage the Anti-Lock Braking System on a wet road

What causes the glow of the reddish areas visible primarily in the spiral arms? Clouds of gas are being heated by ultraviolet light from nearby, recently formed stars. Dust grains are colliding and becoming heated in the dense spiral arms. Light produced from just outside the central black hole is heating the gas in the spiral arms. The stars forming in the dense arms are primarily small, cool, reddish stars

2. The four kinds of friction include all but one of the following: A. Static B. Rolling C. Centrifugal D. Sliding E. Kinetic

Hot Questions

$\square $ Answer Bank KE: 1000.0 J PE: 3000.0 J KE: 0J $PE:4000.0J$ KE: 2000.0 J PE: 2000.0 J KE: 4000.0 J PE: 0J

Learning Log: How do you think you get something to have more kinetic energy?

If a UV light unit has four lamps in it, and each lamp is 7-watt, it is known as a __ 7-watt unit 28-watt unit 11-watt unit 3-watt unit

10. What is the mass of a meteorite that is traveling towards Earth at $1,760m/s$ with a momentum of $33,400kgm/s$

Where is the energy coming from in the lab (where does it start)? A Potential energy in the Cheeto B Potential energy in the water C Kinetic energy inside the water D Kinetic energy in the Cheeto

What should happen to the temperature of the water? A It stays the same B It goes down C It goes up

9. Your local weather report announces that the barometric pressure is 30.44 inHg. Convert this pressure to psi, atm torr, and Pa.

Express the temperature, 275.18 K in degrees Celsius. $548.33^{\circ }C$ $274.17^{\circ }C$ $2.03^{\circ }C$ $120.88^{\circ }C$ $22.78^{\circ }C$

Hubble's Law has led physicists and astronomers to the hypothesis that the universe is expanding. True False

Newton determined that the force of gravity on an object is proportional to its mass causing its mass to be canceled out (Newton's second law) and resulting in a constant acceleration. If the laws of physics are universal, then Newton should be able to apply his discoveries about gravity on Earth to the motion of the planets in our Solar System. Newton's third law says that for every force there is an equal reaction force in the opposite direction. What does this imply about the force of gravity associated with a person standing on the Earth? Choose one: A. The force of gravity on the person cancels out to zero. B. The Earth's gravity pulls downward on the person but also pushes upward on them. C. The Earth's gravity pulls downward on the person, and the person's gravity pulls upward on the Earth. D. There is twice as much gravitational force on the person than there would be if it weren't for Newton's third law.