Answer:
a) Ws = 2.548 J
b) Wf = 1.153 J
c) v = 1.923 m / s
Explanation:
a) The work done by the spring force
Ws = ½ * k * x²
Ws = ½ * 260 N/m *0.14² m
Ws = 2.548J
b) The increase in thermal energy can by find using
Et = Wf
Wf = µ * m *g * x
Wf = 0.42 * 2.0 kg *9.8 m/s² * 0.14m
Wf = 1.153 J
c) The speed just as the block reaches can by fin using
EK = Ws + Et
Ek = ( 2.548 + 1.153 ) J = 3.7 J
Ek = ½ * m * v²
v² = 2* Ek / m
v = √[2 * 3.7 J / 2.0 kg]
v = 1.923 m / s
Answer:
6. W = 3 m g h
Explanation:
Displacement in moving from first floor to the fourth floor is 3h, and the total energy consumed in this process is (3.m.g.h) which is equal to the work done.
According to the work-energy equivalence the change in energy of a system is equal to the work done.
Here, change in potential energy:
![\Delta PE=m.g(\Delta h)](https://tex.z-dn.net/?f=%5CDelta%20PE%3Dm.g%28%5CDelta%20h%29)
![\Delta PE=3mgh](https://tex.z-dn.net/?f=%5CDelta%20PE%3D3mgh)
![\therefore W=\Delta PE](https://tex.z-dn.net/?f=%5Ctherefore%20W%3D%5CDelta%20PE)
![W=3mgh](https://tex.z-dn.net/?f=W%3D3mgh)
Answer:
μ₁ = 0.1048
μ₂ = 0.1375
Explanation:
Using static equation can find in both point the moment and the forces so:
∑ M = F *d , ∑ F = 0
∑ M A = 0
N₁ * 3 - 200 * 9.81 * 1.5 = 0
N₁ = 981
∑ M y = 0
N₂ + 300 * ³/₅ - 981 - 20 * 9.81 = 0
N₂ = 997.2 N
∑ M C = 0
F₁ * 1.75 - 300 * ⁴/₅ * 0.75 = 0
F₁ = 102.86
∑ M B = 0
300 * ⁴/₅ * 1 - F₂ * 1.75 = 0
F₂ = 137.14 N
The Force F1 and F2 related the coefficients of static friction
F₁ = μ₁ * N₁ ⇒ 102.86 N = μ₁ * 981 ⇒ μ₁ = 0.1048
F₂= μ₂ * N₂ ⇒ 137.14 N = μ₂ * 997 ⇒ μ₂ = 0.1375
Applying conservation of momentum
Quarterback mass = 80 kg
ball mass = 0.43 kg
Initially both together but horizontal velocity of both 0
initial momentum = 0
Final momentum = 15*0.43 - 80v
initial = final (law of conservation of momentum)
6.45 = 80v
v = 0.08 m/s
Answer:
Why do the Sun, Moon and stars appear to move across the sky cause our earth is rotating or spinning on his Axis.
hope it helps!