Answer:
The work done to get you safely away from the test is 2.47 X 10⁴ J.
Explanation:
Given;
length of the rope, L = 70 ft
mass per unit length of the rope, μ = 2 lb/ft
your mass, W = 120 lbs
mass of the 70 ft rope = 2 lb/ft x 70 ft
= 140 lbs.
Total mass to be pulled to the helicopter, M = 120 lbs + 140 lbs
= 260 lbs
The work done is calculated from work-energy theorem as follows;
W = Mgh
where;
g is acceleration due gravity = 32.17 ft/s²
h is height the total mass is raised = length of the rope = 70 ft
W = 260 Lb x 32.17 ft/s² x 70 ft
W = 585494 lb.ft²/s²
1 lb.ft²/s² = 0.0421 J
W = 585494 lb.ft²/s² = 2.47 X 10⁴ J.
Therefore, the work done to get you safely away from the test is 2.47 X 10⁴ J.
Answer:
D
Explanation:
because two vectors which align in the same line adds one to another
To solve this problem it is necessary to apply the concepts related to heat exchange in the vegetable and water.
By definition the exchange of heat is given by
![Q =mc\Delta T](https://tex.z-dn.net/?f=Q%20%3Dmc%5CDelta%20T)
where,
m = mass
c = specific heat
= Change in temperature
Therefore the total heat exchange is given as
![\Delta Q = Q_w+Q_v](https://tex.z-dn.net/?f=%5CDelta%20Q%20%3D%20Q_w%2BQ_v)
![\Delta Q = m_wc_w(T_i-T_f)+m_vc_v(T_i-T_f)](https://tex.z-dn.net/?f=%5CDelta%20Q%20%3D%20m_wc_w%28T_i-T_f%29%2Bm_vc_v%28T_i-T_f%29)
Our values are given as,
Total mass is
= 200lb ,however the mass of solid vegetable and water is given as,
![m_v= 0.4*200lb = 80lb](https://tex.z-dn.net/?f=m_v%3D%200.4%2A200lb%20%3D%2080lb)
![m_w=0.6*200lb=120lb](https://tex.z-dn.net/?f=m_w%3D0.6%2A200lb%3D120lb)
![T_i = 183\°F\\T_f = 22\°F\\c_w = 1Btu/lbF\\c_v = 0.24Btu/lbF](https://tex.z-dn.net/?f=T_i%20%3D%20183%5C%C2%B0F%5C%5CT_f%20%3D%2022%5C%C2%B0F%5C%5Cc_w%20%3D%201Btu%2FlbF%5C%5Cc_v%20%3D%200.24Btu%2FlbF)
Replacing at our equation we have,
![\Delta Q = m_wc_w(T_i-T_f)+m_vc_v(T_i-T_f)](https://tex.z-dn.net/?f=%5CDelta%20Q%20%3D%20m_wc_w%28T_i-T_f%29%2Bm_vc_v%28T_i-T_f%29)
![\Delta Q = (120)(1)(183-22)+(80)(0.24)(183-22)](https://tex.z-dn.net/?f=%5CDelta%20Q%20%3D%20%28120%29%281%29%28183-22%29%2B%2880%29%280.24%29%28183-22%29)
![\Delta Q = 22411.2Btu](https://tex.z-dn.net/?f=%5CDelta%20Q%20%3D%2022411.2Btu)
Therefore the heat removed is 22411.2 Btu
A nearly extinct species is an endangered species
Answer:
B) 8 T.
Explanation:
For an ideal gas , the gas law that it follow is as follows
P₁V₁ / T₁ = P₂ V₂ /T₂
This law is followed by all the gases whether mono atomic or diatomic.
In this case following information are given
P₂ / P₁ = 3
V₂ / V₁ = 3
T₁ = T
T₂ = ?
From the gas law formula given , we have
![T_2 =\frac{P_2\times V_2\times T_1}{P_1\times V_1}](https://tex.z-dn.net/?f=T_2%20%3D%5Cfrac%7BP_2%5Ctimes%20V_2%5Ctimes%20T_1%7D%7BP_1%5Ctimes%20V_1%7D)
![V_2 = \frac{P_2}{P_1} \times\frac{V_2}{V_1}\times T](https://tex.z-dn.net/?f=V_2%20%3D%20%5Cfrac%7BP_2%7D%7BP_1%7D%20%5Ctimes%5Cfrac%7BV_2%7D%7BV_1%7D%5Ctimes%20T)
= 3 X 3 T
= 9 T
Change in temperature = 9T - T = 8 T.