A space-walking astronaut has become detached from her spaceship. She's floating in space with her handy tool belt attached to h
1 answer:
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Answer:
7.5 m/s
Explanation:
We can find its velocity when it reaches the buoy by applying one of Newton's equations of motion:
where v = final velocity
u = initial velocity
a = acceleration
s = distance traveled
From the question:
u = 28 m/s
a = -4
s = 91 m
Therefore:
The velocity of the boat when it reaches the buoy is 7.5 m/s.
Answer:
1. 31,536,000 seconds
2. Car B traveled a longer distance
3. Volume of box = 0.235887 cubic meters
Explanation:
Q1. Age in seconds
1 year = 365 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
Therefore 1 year = 365 x 24 x 60 x 60 = 31,536,000 seconds
In scientific notation this would be
Q2. Comparing km and miles
Given:
1 km = 1000m and 1 m = 3.3ft, I km = 1000 x 3.3 = 3300 ft.
Convert Car A distance of 25.7km to feet :
25.7 km. = 25. 7 x 3300 ft. = 84,810 ft.
For Car B that traveled 20 miles,
20 miles = 20 x 5280 = 105,600 ft.
Since 105,600 > 84,810, car B traveled a longer distance
Q3. Volume of wooden box
The wooden box is in the shape of a rectangular prism
It volume is L x W x H
Volume = 1.525 x 0.30 x 0.5156 = 0.235887 cubic meters
Remember that sound intensity decreases in inverse proportion to the distance squared. So, to solve this we are going to use the inverse square formula: 
where
is the intensity at distance 2
is the intensity at distance 1
is distance 2
is distance 1
We can infer for our problem that
, 
, and 
. Lets replace those values in our formula to find :
dB
We can conclude that the intensity of the sound when is <span>3 m from the source is 30 dB.</span>
where
We can infer for our problem that
We can conclude that the intensity of the sound when is <span>3 m from the source is 30 dB.</span>