What does nuclear fusion in stars create? Chemical compounds Black holes New elements Asteroids
2. Why was the International System of Units developed? __
What is the de Broglie wavelength of a 11.5 g hummingbird flying at 100. mph? Round your answer to 3 significant digits. 1mile=1.6093km
The mass of a neutron is approximately equal to that of a __ proton electron
The ladder force model puts the officer in the middle, at the hub of force options. True False
A cell phone falls off a balcony. It's height (in feet)is given by the formula f(t)=-16t^2+13.4t+150 , where t is measured in seconds. How long will it take the cell phone to hit the ground? Round your answers to three decimal places.
Which object from the choices below doesn't have kinetic energy but it has potential energy? A person climbing a ladder A car that is slowing down A battery in a pair of headphones A person riding an elevator upward
A stone is thrown at an angle of 30^circ above the horizontal from the top edge of a cliff with an initial speed of 12m/s A stop watch measures the stone's trajectory time from top of cliff to bottom to be 5.6 s. What is the height of the cliff? (g=9.8m/s^2 and air resistance is negligible) 197 m 120 m 58 m 154 m
Heavy visual mass must always have a heavy physical weight. Select one: True False
(1) 3. How can scientists detect dark energy using evidence? Scientists can see the bending of light due to the gravitational force of matter that cannot otherwise be detected. Scientists have detected dark matter in experiments. Scientists can see dark energy directly through ordinary light waves.
You are-tonsidering whether to buy a house for $\$ 80,000$ or another identical house located near high-voltage electric power lines, for $\$ 70,000$ Assume that it has been established that living near high-voltage lines increases the risk of cancer due to electromagnetic fields (EMFs). True or False: If you choose the $\$ 70,000$ house, the radiation from EMFs is not an externality. True X False
Question 1 Light travels faster in: 1. warm air 2. cool air 3. a vacuum. Question 2 When white light goes from air into water,the color that refracts the most is: 1. red 2. orange 3. green 4. violet 5. all refract the same amount. Explain.
What is the maximum number of electrons that the $7^{th}$ energy level can accomodate? 8 32 49 98
A piece of chocolate melts in your mouth This is an example of heat conduction. heat convection. heat radiation. thermal expansion. none of the above.
Question 4 Which of the following objects would require the use of a small-scale model? An atom The planet Saturn The highway system in Florida The path of an ocean current
Of an initial amount of 1000 g of lead-210, how much will remain in 160 years?Lead-210 decays at a rate of $3.15\% /yr$ $\square $ g (Round to one decimal place as needed.)
Which symbol represents a gamma ray? A. $\alpha $ B. $\gamma $ C. $\beta ^{-}$ D. $\beta ^{+}$
Select the correct answer. Which of Newton's laws states that "every action has an equal and opposite reaction"? A. first B. third C. second D. fourth
Refraction results from changes in light's speed. all of the above incident angles. frequency.
Essay: In your own words, explain why a simple pendulum's period does not depend on the mass on the end of the pendulum. $\square $
