Answer: The velocity at different marked time points are given as
t1 = -
t2 = +
t3 = +
t4 = -
t5 = 0
Explanation:
The slope of the tangent of the curve indicates the instantaneous velocity. So if the slope of the tangent is positive, that Is, the tangent makes a positive angle (above the horizontal axis) with the horizontal
axis, then the velocity at this point is positive, and if the slope of the tangent is negative, that is the tangent makes a negative angle with the horizontal axis (below the horizontal axis), then the velocity at this point is negative.
When the tangent of the line is parallel to the horizontal axis, the velocity is 0.
From the position-time graph attached, the sign on the instantaneous velocity for each time marked on the graph is given below
t1 = -
t2 = +
t3 = +
t4 = -
t5 = 0
QED!
Answer:
option b
Explanation:
the heavier one will have twice the kinetic energy of the lighter one
Answer: A little more that 5 Kg for a healthy person
Explanation: First, we know the following:
The regular adult has from 9 to 12 pints of blood. This is around 5 liters for a healthy male adult.
The human body is composed mostly on water, around 80%.
Blood is mostly composed on plasma, which makes blood thicker than water.
Knowing that, almost all the body is compose of water, it is safe to think that blood density should be near to that of water but higher.
The density on water is a know value. Which makes the following true:
<em>1 Liter of Water weights 1 Kg</em>
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It could be said then, that the total mass of blood for a healthy person should be a little more that 5 kgs.
Answer:
2513.6 W
Explanation:
Acoustic power = sound intensity × area of hemisphere
Sound intensity = 1 W/m^2
Area of hemisphere = 2πr^2 = 2×3.142×20^2 = 2513.6 m^2
Acoustic power = 1 W/m^2 × 2513.6 m^2 = 2513.6 W
