| Your Results | Global Average | |
|---|---|---|
| Questions | 5 | 5 |
| Correct | 0 | 3.20 |
| Score | 0% | 64% |
A major difference between sound waves and light waves is which of the following?
all of these are correct |
|
a sound wave is mechanical while a light wave is electromagnetic |
|
a sound wave cannot travel through a vacuum |
|
a sound wave is much slower than a light wave |
A vibrating object produces a sound wave that travels outwardly from the object through a medium (any liquid or solid matter). The vibration disturbs the particles in the surrounding medium, those particles disturb the particules next to them, and so on, as the sound propagates away from the vibration.
The formula \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) applies to which of Newton's laws?
third law of motion |
|
first law of motion |
|
second law of motion |
|
universal gravitation |
Newton's law of universal gravitation defines gravity: All objects in the universe attract each other with an equal force that varies directly as a product of their masses, and inversely as a square of their distance from each other. Expressed as a formula: \(\vec{F_{g}} = { Gm_{1}m_{2} \over r^2}\) where r is the distance between the two objects and G is the gravitational constant with a value of 6.67 x 10-11.
The gravitational interaction of Earth and the Moon is responsible for which of these?
day and night cycle |
|
the northern lights |
|
tides |
|
seasons |
Tides are caused by the gravitational interaction of Earth and the Moon.
Velocity is the rate at which an object changes position. What is the formula for velocity?
\(\vec{v} = { t \over \vec{d} } \) |
|
\(\vec{v} = \vec{d}t \) |
|
none of these |
|
\(\vec{v} = { \vec{d} \over t } \) |
Velocity is the rate at which an object changes position. Rate is measured in time and position is measured in displacement so the formula for velocity becomes \(\vec{v} = { \vec{d} \over t } \)
In the water cycle, infiltration is most closely related to:
rivers |
|
water table |
|
runoff |
|
oceans |
The water then accumulates as runoff and eventually returns to bodies of water or is absorbed into the Earth (infiltration) and becomes part of the water table, an underground resevoir of fresh water.