Answer:
11.85 kg m/s
Explanation:
impulse = mass ( change in velocity )
= mass ( final velocity - initial velocity )
= 0.150 ( 32.0 - (-47.0))
= 0.150 ( 32.0 +47.0)
= 0.150 (79)
= 11.85 kg m/s
Answer:
meters
Explanation:The question ask for the maximum value of the function f(t) which can be find by find the maxima of the function
The maxima of the function occurs when the slope is zero. i.e.
![\frac{df}{dt} =0\\\frac{df}{dt} =\frac{d}{dt} (-4.9t^2+16t+2)\\\frac{df}{dt} =-4.9*2t+16\\-9.8t+16=0\\t=16/9.8\\t=1.63 secs](https://tex.z-dn.net/?f=%5Cfrac%7Bdf%7D%7Bdt%7D%20%3D0%5C%5C%5Cfrac%7Bdf%7D%7Bdt%7D%20%3D%5Cfrac%7Bd%7D%7Bdt%7D%20%28-4.9t%5E2%2B16t%2B2%29%5C%5C%5Cfrac%7Bdf%7D%7Bdt%7D%20%3D-4.9%2A2t%2B16%5C%5C-9.8t%2B16%3D0%5C%5Ct%3D16%2F9.8%5C%5Ct%3D1.63%20secs)
Hence the maxima occurs at t=1.63 seconds
The maximum value of f is
![f(1.63)=-4.9(1.63^2)+16(1.63)+2\\f(1.63)=15.06\\](https://tex.z-dn.net/?f=f%281.63%29%3D-4.9%281.63%5E2%29%2B16%281.63%29%2B2%5C%5Cf%281.63%29%3D15.06%5C%5C)
hence maximum height is found to be
meters
Answer:
(a) Vf = 128 ft/s
(b) K.E = 122.8 Btu
Explanation:
(a)
In order to find the velocity of the object just before striking the surface of earth or the final velocity, we use 3rd equation of motion:
2gh = Vf² - Vi²
where,
g = 32.2 ft/s²
h = height = 253 ft
Vf = Final Velocity = ?
Vi = Initial Velocity = 10 ft/s
Therefore,
(2)(32.2 ft/s²)(253 ft) = Vf² - (10 ft/s)²
16293.2 ft²/s² + 100 ft²/s² = Vf²
Vf = √(16393.2 ft²/s²)
<u>Vf = 128 ft/s</u>
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(b)
The kinetic energy of the object before it hits the surface of earth is given by:
K.E = (0.5)(m)(Vf)²
where,
m = mass of object = 375 lb
K.E = Kinetic energy of object before it strikes the surface of earth = ?
Therefore,
K.E = (0.5)(375 lb)(128 ft/s)²
K.E = 3073725 lb.ft²/s²
Now, converting this to Btu:
K.E = (3073725 lb.ft²/s²)(1 Btu/25037 lb.ft²/s²)
<u>K.E = 122.8 Btu</u>
Its an electrochemical cell that derives electrical energy from spontaneous redox reactions taking place within the cell.