aceleración= velocidad final - velocidad inicial ÷ el tiempo
a= 10-20÷5= -2 m/s
I would say nitrogen, because we couldn't breather without nitrogen.
Answer: The coefficient of friction is 0.35
Explanation:
We can write the friction force as:
F = N*μ
Where N is the normal force between the refrigerator and the ground, as the full weight of the refrigerator is acting on the ground, the normal force will be exactly equal to the weight of the refrigerator, then:
N = 650N
And μ is the coefficient of friction.
And for this case, the force is 230N, then we have:
F = N*μ
230N = 650N*μ
(230N/650N) = μ = 0.35
Notice that the distance did not matter for this calculation.
Explanation:
It is given that,
Mass of the truck, m = 2000 kg
Initial velocity of the truck, u = 34 km/h = 9.44 m/s
Final velocity of the truck, v = 58 km/h = 16.11 m/s
(a) Change in truck's kinetic energy, ![\Delta E=\dfrac{1}{2}m(v^2-u^2)](https://tex.z-dn.net/?f=%5CDelta%20E%3D%5Cdfrac%7B1%7D%7B2%7Dm%28v%5E2-u%5E2%29)
![\Delta E=\dfrac{1}{2}\times 2000\ kg\times (16.11^2-9.44^2)](https://tex.z-dn.net/?f=%5CDelta%20E%3D%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%202000%5C%20kg%5Ctimes%20%2816.11%5E2-9.44%5E2%29)
![\Delta E=170418.5\ J](https://tex.z-dn.net/?f=%5CDelta%20E%3D170418.5%5C%20J)
![\Delta E=1.7\times 10^5\ J](https://tex.z-dn.net/?f=%5CDelta%20E%3D1.7%5Ctimes%2010%5E5%5C%20J)
(b) Change in momentum of the truck, ![\Delta p=m(v-u)](https://tex.z-dn.net/?f=%5CDelta%20p%3Dm%28v-u%29)
![\Delta p=2000\ kg\times (16.11-9.44)](https://tex.z-dn.net/?f=%5CDelta%20p%3D2000%5C%20kg%5Ctimes%20%2816.11-9.44%29)
![\Delta p=13340\ kg-m/s](https://tex.z-dn.net/?f=%5CDelta%20p%3D13340%5C%20kg-m%2Fs)
Hence, this is the required solution.
The mass on the left has a downslope weight of
W1 = 3.5kg * 9.8m/s² * sin35º = 19.7 N
The mass on the right has a downslope weight of
W2 = 8kg * 9.8m/s² * sin35º = 45.0 N
The net is 25.3 N pulling downslope to the right.
(a) Therefore we need 25.3 N of friction force.
Ff = 25.3 N = µ(m1 + m2)gcosΘ = µ * 11.5kg * 9.8m/s² * cos35º
25.3N = µ * 92.3 N
µ = 0.274
(b) total mass is 11.5 kg, and the net force is 25.3 N, so
acceleration a = F / m = 25.3N / 11.5kg = 2.2 m/s²
tension T = 8kg * (9.8sin35 - 2.2)m/s² = 27 N
Check: T = 3.5kg * (9.8sin35 + 2.2)m/s² = 27 N √
hope this helps. :)