One well-known application of density is determining whether or not an object will float on water. If the object's density is less than the density of water, it will float; if its density is less than that of water, it will sink.In fact, submarines dive below the surface of the water by emptying their ballast tanks
<span>3.2x10^-2 seconds (0.032 seconds)
This is a simple matter of division. I also suspect it's an exercise in scientific notation, so here is how you divide in scientific notation:
9.6 x 10^6 m / 3x10^8 m/s
First, divide the significands like you would normally.
9.6 / 3 = 3.2
And subtract the exponent. So
6 - 8 = -2
So the answer is 3.2 x 10^-2
And since the significand is less than 10 and at least 1, we don't need to normalize it.
So it takes 3.2x10^-2 seconds for the radio signal to reach the satellite.</span>
<span>Her center of mass will rise 3.7 meters.
First, let's calculate how long it takes to reach the peak. Just divide by the local gravitational acceleration, so
8.5 m / 9.8 m/s^2 = 0.867346939 s
And the distance a object under constant acceleration travels is
d = 0.5 A T^2
Substituting known values, gives
d = 0.5 9.8 m/s^2 (0.867346939 s)^2
d = 4.9 m/s^2 * 0.752290712 s^2
d = 3.68622449 m
Rounded to 2 significant figures gives 3.7 meters.
Note, that 3.7 meters is how much higher her center of mass will rise after leaving the trampoline. It does not specify how far above the trampoline the lowest part of her body will reach. For instance, she could be in an upright position upon leaving the trampoline with her feet about 1 meter below her center of mass. And during the accent, she could tuck, roll, or otherwise change her orientation so she's horizontal at her peak altitude and the lowest part of her body being a decimeter or so below her center of mass. So it would look like she jumped almost a meter higher than 3.7 meters.</span>
