True or False: Magnitude zero stars have zero brightness. Select one: True False
What is the minimum number of ice cubes at 0.0^circ C needed to cool 240 mL of coffee at 75^circ C to 0.0^circ C ? Assume each ice cube is 18.0 g of water and the density of the coffee is 1.0g/mL Delta H_(fus)=334J/g C_(H_(2)O,I)=4.18J/gcdot ^circ C Number of ice cubes=[?] Hint:The energy from the coffee cooling melts the ice cubes. Round to the nearest whole ice cube.
What is the total kinetic energy before the collision? What is the total kinetic energy after the collision?3 Which of the following is true? i. Kinetic energy and momentum are both conserved. ii. Only momentum is conserved but energy is lost.
c. A2kg object moving East at a velocity of 21 meters per second strikes a 20 kilogram object that was at rest. After the collision the 2 kg object moves east with a velocity 1m/s and the 20 kg object moves east with a velocity of 2m/s What is the total momentum of the system before collision.^2 What is the total momentum of the system after the collision.
Which of the following surfaces can cause a loss of traction? Wet pavement Gravel roads Icy pavement All choices are correct
Wind turbines are designed to carry out which type of energy transformation? A. Kinetic energy to sound energy, B. Gravitational Potential energy to electrical energy C. Electrical energy to light energy, D. Kinetic energy to electrical energy
A sound wave with an intensity of 25W/cm^2 is totally reflected. The intensity reflection coefficient is: 100% 50W/cm^2 25% 25W/cm^2
Lightning is the result of a build-up of electric charge difference caused by: (a). Violent collision of raindrops. (b). Rapid coalescence of cloud droplets. (c). Riming due to sudden temperature changes. (d). Freezing of supercooled liquid water droplets. (e). Collision of graupe and ice crystals
What is the final temperature of a system with a volume of 88.70mL with an initial temperature of 56.00 Celsius and the volume increases to 899.0mL? 242.4K 32.46K 3335K 57.98K
Multiple Choice 2 points If an air parcel is completely at rest, which of the following forces can make the parcel begin to move? (a) friction (b) centripetal (c) pressure gradient (d) gravity (e) Coriolis
1. Choose the correct statement or equation. When a wave in a string reflects from an open or flexible end, the reflected wave has the same wavelength and amplitude as the original wave. When a wave in a string reflects from a fixed end, the reflected wave has the same wavelength and amplitude as the original wave.
In what ways are meteorites different from meteors? What is the probable origin of each? Meteors typically come from comets that have passed through the solar system; their solid material is freed when the ice is vaporized by the heat of the Sun. Meteorites miss the atmosphere whereas meteors hit the outer layers only. Most meteors come from Mars and carry important information about the past of the red planet. Meteorites are large enough to withstand the violent passage through Earth's atmosphere, whereas meteors burn up from the heat of friction. Most meteorites, on the other hand, are from asteroids or from debris kicked up on the Moon or Mars during an impact.
If a rock is dropped from a height of 87 ft, its poistion t seconds after it is dropped until it hits the ground is given by the function $s(t)=-16t^{2}+87$ Round values below to 3 decimal places. How long does it take the rock to hit the ground? $\square $ seconds Find the average velocity of the rock from when it is released until when it hits the ground. $\square $ feet per second What time after the rock is thrown will its instantaneous velocity be equal to its average velocity? (Apply the Mean Value Theorem) $\square $ seconds after it is thrown
The bending or change in angle of light as it passes through a lens is called $\square $
Photons of a certain infrared light have an energy of $1.91\times 10^{-19}J$ (a) What is the frequency of this IR light? $\square $ Hz (b) Use $\lambda =c/f$ to calculate its wavelength in nanometers. $\square $ nm
The outer planets of the solar system were formed by asteroid agglomeration comet collisions gravitational forces temperature increases
Multiple Choice 2 points Step 3 of Part 2: The flashlight is shining to an azimuth of 225 degrees. What is the azimuth of the shadow? 0 degrees 45 degrees 90 degrees 180 degrees
1) The height of the Washington Monument is measured to be 170 m on a day when the temperature is $35.0^{\circ }C$ What will its height be on a day when the temperature falls to $-10.0^{\circ }C$ Although the monument is made of limestone, assume that its thermal coefficient of expansion is the same as marble's.
A point is subjected to 5 ksi biaxial tension. The diameter of the corresponding Mohr's circle is most nearly: O 5 ksi 7.07 ksi 10 ksi
A ball is thrown vertically upward. After r seconds, it's height him feet) is given by the function $h(t)=40t-16t^{2}$ After how long will It reach its maximum height? Do not round your answer. Time: $\square $ seconds
