Moonquakes on the Moon were detected by:
A) the radar observations over time from Earth.
B) the seismographs left these by the Apollo astronauts.
C) laser beams reflected off mirrors left on the Moon by Apollo missions.
D) seismographs attached to the Russian Lunar rovers.
E) telescopic observations of lunar landslides.
B
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Granulation is caused by convection currents just below the photosphere
a. True b. False Indicate whether the statement is true or false
Compound Microscope: The focal lengths of the objective lens and the eyepiece in a microscope are 2.90 mm and 2.50 cm, respectively. An object is placed 3.00 mm from the objective. The image of this object is viewed with the eyepiece adjusted for minimum eyestrain for persons with a near point of 25 cm. What is the distance between the objective and the eyepiece?
A. 9.9 cm B. 9.0 cm C. 15 cm D. 11 cm E. 13 cm
John is carrying a shovelful of snow. The center of mass of the 3.00 kg of snow he is holding is 15.0 cm from the end of the shovel. He is pushing down on the opposite end of the shovel with one hand and holding it up 30.0 cm from that end with his other hand. Ignore the mass of the shovel. Sarah says that his hand pushing down on the shovel must be exerting a greater force than the hand pushing up. James says it is just the reverse. Which one, if either, is correct?
A. Sarah, because the hand pushing down must exert a greater force to match the torque exerted by the snow. B. James, because, depending on the location of the axis of rotation, the hand pushing down can counteract the torque exerted by the snow. C. James, because the hand pushing up must exert a force that equals the sum of the force of the hand pushing down and the weight of the snow. D. James, because both (b) and (c) above are correct. E. Neither, because the hands exert forces of equal magnitudes.
The Doppler technique can be used to measure the orbital period of a planet by
A) measuring the asymmetries in the velocity curve. B) measuring the amount by which the starlight is reduced when the planet transits. C) measuring the speed at which the star orbits the mutual center-of-mass of the star and planet. D) measuring the time it takes for the star's line-of-sight velocity to cycle from peak to peak.