Answer:(a)360N,(b)171N,(c)2.702m
Explanation:
(a)Maximum Friction Force =![\mu \left ( N\right )=0.4\times \left ( 740+160\right )](https://tex.z-dn.net/?f=%5Cmu%20%5Cleft%20%28%20N%5Cright%20%29%3D0.4%5Ctimes%20%5Cleft%20%28%20740%2B160%5Cright%20%29)
=360 N
![cos\theta =\frac{3}{5}](https://tex.z-dn.net/?f=cos%5Ctheta%20%3D%5Cfrac%7B3%7D%7B5%7D)
![sin\theta =\frac{4}{5}](https://tex.z-dn.net/?f=sin%5Ctheta%20%3D%5Cfrac%7B4%7D%7B5%7D)
(b)Moment about Ground Point
![740\times 1\times cos\theta +2.5\times 160\times cos\theta -N_15sin\theta](https://tex.z-dn.net/?f=740%5Ctimes%201%5Ctimes%20cos%5Ctheta%20%2B2.5%5Ctimes%20160%5Ctimes%20cos%5Ctheta%20-N_15sin%5Ctheta%20)
![N_1tan\theta =1140](https://tex.z-dn.net/?f=N_1tan%5Ctheta%20%3D1140)
![N_1=171 N](https://tex.z-dn.net/?f=N_1%3D171%20N)
![N_1=f=171 N](https://tex.z-dn.net/?f=N_1%3Df%3D171%20N)
(c)
![740\times x\times cos\theta +2.5\times 160\times cos\theta -N_15sin\theta](https://tex.z-dn.net/?f=740%5Ctimes%20x%5Ctimes%20cos%5Ctheta%20%2B2.5%5Ctimes%20160%5Ctimes%20cos%5Ctheta%20-N_15sin%5Ctheta%20)
Here maximum friction force can be 360 N
Therefore ![N_1=360 N](https://tex.z-dn.net/?f=N_1%3D360%20N)
Where x is the maximum distance moved by man along the ladder
![360\times 5\times \frac{4}{3}=740x+160\times 2.5](https://tex.z-dn.net/?f=360%5Ctimes%205%5Ctimes%20%5Cfrac%7B4%7D%7B3%7D%3D740x%2B160%5Ctimes%202.5)
740x=2000
x=2.702m
Answer: True
Explanation:
A force must be applied to set a stationary object in motion.
Answer:
P₁- P₂ = 91.1 10³ Pa
Explanation:
For this exercise we will use Bernoulli's equation, where point 1 is at the bottom of the house and point 2 on the second floor
P₁ + ½ ρ v₁² + ρ g y₁ = P₂ + ½ ρ v₂² + ρ g y₂
P1-P2 = ½ ρ (v₂² - v₁²) + ρ g (y₂-y₁)
In the exercise they give us the speeds and the height of the turbid, so we can calculate the pressure difference
For heights let's set a reference system on the ground floor of the house, so we have 5m for the second floor and an entrance at -2m
P₁-P₂ = ½ 1.0 10³ (7² - 2²) + 1.0 10³ 9.8 (5 + 2)
P₁-P₂ = 22.5 10³ + 68.6 10³
P₁- P₂ = 91.1 10³ Pa