We have the relation

where
denotes the velocity of a body A relative to another body B; here I use B for boat, E for Earth, and R for river.
We're given speeds


Let's assume the river flows South-to-North, so that

and let
be the angle made by the boat relative to East (i.e. -90° corresponds to due South, 0° to due East, and +90° to due North), so that

Then the velocity of the boat relative to the Earth is

The crossing is 153.0 m wide, so that for some time
we have

which is minimized when
so the crossing takes the minimum 30.0 s when the boat is pointing due East.
It follows that

The boat's position
at time
is

so that after 30.0 s, the boat's final position on the other side of the river is

and the boat would have traveled a total distance of

Answer:
because it is less dense than the surrounding air
Explanation:
The work that is done when twice the load is lifted twice the distance is
four times as much
The net work performed by forces acting on an object equals the change in kinetic energy, according to the work-energy theorem.
when an item slows down, the net work applied to it decreases, its change in kinetic energy is negative, and its ultimate kinetic energy is less than its starting kinetic energy. When an item accelerates, positive net work is done on it. All the forces acting on an item must be taken into consideration when determining the net work. You will obtain an incorrect result if you exclude any forces that affect an item or if you add any forces that do not affect it.
Hence The work that is done when twice the load is lifted twice the distance is four times as much
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Answer:
200 mL
Explanation:
Given that,
Initial volume, V₁ = 300 mL
Initial pressure, P₁ = 0.5 kPa
Final pressure, P₂ = 0.75 kPa
We need to find the final volume of the sample if pressure is increased at constant temperature. It is based on Boyle's law. Its mathematical form is given by :

V₂ is the final volume

So, the final volume of the sample is 200 mL.