Answer:
4050 gallons
Explanation:
In first half and hour both pumps are working property . There for it give, 45
gallons per minute . Half and hour is equal to 30 minutes.After one pump was broken only one pump is working 30 minutes .
For 1st 30 minutes ,( 2 pumps are working )
Gallons = 45 * 30 *2 = 2700 gallons
2nd 30 minutes ( 1 pump is working )
Gallons = 45*30*1 = 1350 gallons
Total gallons = 2700+1350
= 4050 gallons
Answer : The correct option is, (D) Surface tension is caused by cohesion between water molecules on the surface.
Explanation :
Surface tension : It is caused by the cohesion between water molecules on the surface or we can say that it is a tension of the surface of liquid caused by the attraction of the particles which are present on the surface layer by the bulk of the liquid, which tends to minimize surface area.
And due to the surface tension phenomena the shape of the water molecule tend to assume a spherical shape to attain the minimum surface area.
Hence. the correct option is, (D) Surface tension is caused by cohesion between water molecules on the surface.
Answer:
Part a)
Part b)
Part c)
Part d)
Displacement for entire trip = 0
Part e)
Average velocity for entire trip will be zero
Explanation:
Part a)
Displacement after t = 2.4 hours is the straight line distance between initial and final positions
so we have
Part b)
Average velocity is defined as
Part c)
During his return journey the displacement will be same
so average velocity is defined as
Part d)
Displacement for entire trip = 0
as initial and final position will be same
Part e)
Average velocity for entire trip will be zero
The initial velocity is zero
the acceleration is 9.81m/s² due to gravity
the displacement is 145m
Therefore, the formula you use:
d=vinitial*t + 1/2at²
Since v initial is zero we can cancel out the first of the equation which as the product will come out to be 0.
Therefore,
t= √2d/a
=√2(145)/(9.81)
=5.4370...s or to proper sigdigs 5.44s
Hope this helps!