For this case you must first know the definition of density.
D = m / v
where,
m: mass
v: volume.
You can then write the following hypothesis:
IF you know two physical characteristics of an object then you can determine the density. First weigh the object, THEN measure its volume BECAUSE the density is the quotient between the mass and the volume of an object.
Answer:
416.667 m/s
Explanation:
divide the distance by the time
Answer:
Explanation:
Let acceleration of fall be a .
v² = u² + 2as
v = 3.8 m /s
u = 0
s = 3.5 m
3.8² = 0 + 2 x a x 3.5
a = 2.06 m /s²
Since this acceleration is less than g , an upward force is acting on the firefighter in the form of friction . Let this force be F . Let mass of the firefighter be m .
m = 765 / 9.8
= 78.06 kg
mg - F = ma
765 - F = 78.06 x 2.06
765 - F = 160.8
F = 604.2 N .
a) mass
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The reason scientists use light years instead of kilometres is becasue a light year is the distance traveled by light in one year, and if we actually did the math (ill just give it to you)

to put that into perspective a kilometer is 1000 meters or

. if they mesured everything in kilometers they would have to use even bigger numbers than they already do.