Suppose that Mercury grew to its present size in 1 million years through the accretion of particles averaging 100 g each. On average how many particles did Mercury capture each second? Note: Mercury has a mass of 3.3 × 10^23 kg and a radius of 2439 km
a. about 24 particles per second
b. about 3.3 × 10^21 particles per second
c. about 67 particles per second
d. about 100 million particles per second
e. about 100 billion particles per second
e
RATIONALE: Using conversions, you can set up an equation like total mass = (mass/time) × time or 3.3 × 10^23 kg = (mass/time) × 1 million years to get (mass/time) = 10 billion kg/s. But the answer they want is in particles/s so write another equation where (particles/time) = (mass/time)/mass or (particles/time) = 10 billion kg/s/0.1 kg or (particles/time) = 100 billion particles/s
You might also like to view...
A satellite is orbiting the earth. If a payload of material is added until it doubles the satellite's mass, the earth's pull of gravity on this satellite will double but the satellite's orbit will not be affected
A) True B) False
To save the most energy when you leave your cool house for an hour or so on a hot day, you should turn the temperature setting on the air conditioner
A) down. B) up. C) off. D) to room temperature.
A primary waste product of nuclear reactors that are designed for only power generation is
A. graphite. B. high-pressure steam. C. radioactive materials. D. enriched uranium.
A block is pushed across a rough horizontal surface from point A to point B by a force (magnitude P = 5.4 N) as shown in the figure. The magnitude of the force of friction acting on the block between A and B is 1.2 N and points A and B are 0.5 m apart. If the kinetic energies of the block at A and B are 4.0 J and 5.6 J, respectively, how much work is done on the block by the force
P between A and B?
a.
2.7 J
b.
1.0 J
c.
2.2 J
d.
1.6 J
e.
3.2 J