The last choice. Two arrows and the arrow up is shorter than the arrow down. Since the guy is falling and he’s opened his chute, he’s slowing down but he’s still falling meaning the force of gravity is stronger than the air resistance.
Answer:
T = 76.39°C
Explanation:
given,
coffee cup temperature = 95°C
Room temperature= 20°C
expression
![T( t ) = 20 + 75 e^{\dfrac{-t}{50}}](https://tex.z-dn.net/?f=T%28%20t%20%29%20%3D%2020%20%2B%2075%20e%5E%7B%5Cdfrac%7B-t%7D%7B50%7D%7D)
temperature at t = 0
![T( 0 ) = 20 + 75 e^{\dfrac{-0}{50}}](https://tex.z-dn.net/?f=T%28%200%20%29%20%3D%2020%20%2B%2075%20e%5E%7B%5Cdfrac%7B-0%7D%7B50%7D%7D)
T(0) = 95°C
temperature after half hour of cooling
![T( t ) = 20 + 75 e^{\dfrac{-t}{50}}](https://tex.z-dn.net/?f=T%28%20t%20%29%20%3D%2020%20%2B%2075%20e%5E%7B%5Cdfrac%7B-t%7D%7B50%7D%7D)
t = 30 minutes
![T( 30 ) = 20 + 75 e^{\dfrac{-30}{50}}](https://tex.z-dn.net/?f=T%28%2030%20%29%20%3D%2020%20%2B%2075%20e%5E%7B%5Cdfrac%7B-30%7D%7B50%7D%7D)
![T( 30 ) = 20 + 75 \times 0.5488](https://tex.z-dn.net/?f=T%28%2030%20%29%20%3D%2020%20%2B%2075%20%5Ctimes%200.5488)
T(30) = 61.16° C
average of first half hour will be equal to
![T = \dfrac{1}{30-0}\int_0^30(20 + 75 e^{\dfrac{-t}{50}})\ dt](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B1%7D%7B30-0%7D%5Cint_0%5E30%2820%20%2B%2075%20e%5E%7B%5Cdfrac%7B-t%7D%7B50%7D%7D%29%5C%20dt)
![T = \dfrac{1}{30}[(20t - \dfrac{75 e^{\dfrac{-t}{50}}}{\dfrac{1}{50}})]_0^30](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B1%7D%7B30%7D%5B%2820t%20-%20%5Cdfrac%7B75%20e%5E%7B%5Cdfrac%7B-t%7D%7B50%7D%7D%7D%7B%5Cdfrac%7B1%7D%7B50%7D%7D%29%5D_0%5E30)
![T = \dfrac{1}{30}[(20t - 3750e^{\dfrac{-t}{50}}]_0^30](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B1%7D%7B30%7D%5B%2820t%20-%203750e%5E%7B%5Cdfrac%7B-t%7D%7B50%7D%7D%5D_0%5E30)
![T = \dfrac{1}{30}[(20\times 30 - 3750 e^{\dfrac{-30}{50}} + 3750]](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B1%7D%7B30%7D%5B%2820%5Ctimes%2030%20-%203750%20e%5E%7B%5Cdfrac%7B-30%7D%7B50%7D%7D%20%2B%203750%5D)
![T = \dfrac{1}{30}[600 - 2058.04 + 3750]](https://tex.z-dn.net/?f=T%20%3D%20%5Cdfrac%7B1%7D%7B30%7D%5B600%20-%202058.04%20%2B%203750%5D)
T = 76.39°C
A. 22 Million...........................................................
Answer:
0.0195 m
Explanation:
= density of hockey puck = 9.45 gcm⁻³ = 9450 kgm³
= diameter of hockey puck = 13 cm = 0.13 m
= height of hockey puck = 2.8 cm = 0.028 m
= density of mercury = 13.6 gcm⁻³ = 13600 kgm³
= depth of puck below surface of mercury
According to Archimedes principle, the weight of puck is balanced by the weight of mercury displaced by puck
Weight of mercury displaced = Weight of puck
![\rho _{m} (0.25)(\pi d_{p}^{2} d ) g = \rho _{p} (0.25)(\pi d_{p}^{2} h_{p} ) g\\\rho _{m} ( d ) = \rho _{p} ( h_{p} )\\(13600) d = (9450) (0.028)\\d = 0.0195 m](https://tex.z-dn.net/?f=%5Crho%20_%7Bm%7D%20%280.25%29%28%5Cpi%20d_%7Bp%7D%5E%7B2%7D%20d%20%29%20g%20%3D%20%5Crho%20_%7Bp%7D%20%280.25%29%28%5Cpi%20d_%7Bp%7D%5E%7B2%7D%20h_%7Bp%7D%20%29%20g%5C%5C%5Crho%20_%7Bm%7D%20%28%20d%20%29%20%3D%20%5Crho%20_%7Bp%7D%20%28%20h_%7Bp%7D%20%29%5C%5C%2813600%29%20d%20%3D%20%289450%29%20%280.028%29%5C%5Cd%20%3D%200.0195%20m)
The force of friction that is acting on the suitcase is the force that opposes the motion of the suitcase.
<h3>What is friction?</h3>
The force that resists the motion between two bodies in contact. There are some materials that reduces friction such as oil in a car engine reduces friction. In this example, friction creates between the motion of suitcase and with the ground.
So we can conclude that the force of friction that is acting on the suitcase is the force that opposes the motion of the suitcase.
Learn more about force here: brainly.com/question/12970081
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