33 terms

# Physics (3: Gravity, Force, & Space)

Multiple Choice Questions (33)
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At high velocities, most of the fuel used in an automobile is used to overcome
air resistance
Balloons rise until
the surrounding air becomes too dense
At an altitude of 220 km, the downward force of gravity on an Earth satellite is
a little bit weaker
Airplanes fly (maintain their altitude) by
pushing air downward
Rockets fly by
pushing burned fuel downward
The storm surge in a hurricane comes from
the low pressure
When an astronaut in space sneezes, his head is snapped back with higher velocity on Earth, because
Wrong! His head is not snapped back with higher velocity
A rail gun
doesn't really accelerate things
The Sun would be a black hole if it were squeezed into a radius
2 miles
The method that would take the least energy to get something to space is
lifting it by an elevator (f the elevator existed)
If an artificial satellite orbited the Earth at 240,000 miles (the distance to the Moon), it would orbit the Earth in a period of
1 month
The time it takes a geosynchronous satellite to orbit the Earth is
1 day
The force of gravity between two people standing next to each other is
small but measurable (flea/10^-7)
You can see where the tropopause is by
looking at the tops of thunderstroms
If satellites fly too low, they will crash because
of stronger gravity
Ice-skaters spin faster by pulling in their arms. This illustrates that
angular momentum is conserved
Someone firing a rifle is pushed back by the rifle. This illustrates that
momentum is conserved
A problem with rail guns is that
the high accelerations can cause damage
The maximum acceleration of the space shuttle is about
3 g's
The lowest practical altitude for a satellite orbiting the Earth is about
600 miles (a few hundred)
For very high velocities, the best kind of rocket to use is
ion rocket
The altitude of a geosynchronous satellite is closest to
22,000 miles
Skyhook, if built, is
a way to get into space using less energy
If you fall for one second, your speed will be approximately
22 mph
Artificial gravity can be created in a spaceship by
accelerating the ship
5 miles/second
The Sun is mostly hydrogen, yet the Earth has very little hydrogen gas. That's because
it escaped to space
The orbit of GPS is
MEO (Medium Earth Orbit)
A geosynchronous satellite orbits the Earth
once every 24 hours
A typical spy satellite can continuously observe a location on the ground for about
one minute
Compared to the weight of the payload, the fuel used in a rocket to orbit typically weighs
over 20 times more
A cubic meter balloon can lift