Answer:
Explanation:
Before it hits the ground:
The initial potential energy = the final potential energy + the kinetic energy
mgH = mgh + 1/2 mv²
gH = gh + 1/2 v²
v = √(2g (H - h))
v = √(2 * 9.81 m/s² * (0.42 m - 0.21 m))
v ≈ 2.0 m/s
When it hits the ground:
Initial potential energy = final kinetic energy
mgH = 1/2 mv²
v = √(2gH)
v = √(2 * 9.81 m/s² * 0.42 m)
v ≈ 2.9 m/s
Using a kinematic equation to check our answer:
v² = v₀² + 2a(x - x₀)
v² = (0 m/s)² + 2(9.8 m/s²)(0.42 m)
v ≈ 2.9 m/s
Answer:
= 14.88 N
Explanation:
Let's begin by listing out the given variables:
M = 2.7 kg, L = 3 m, m = 1.35 kg, d = 0.6 m,
g = 9.8 m/s²
At equilibrium, the sum of all external torque acting on an object equals zero
τ(net) = 0
Taking moment about
we have:
(M + m) g * 0.5L -
(L - d) = 0
⇒
= [(M + m) g * 0.5L] ÷ (L - d)
= [(2.7 + 1.35) * 9.8 * 0.5(3)] ÷ (3 - 0.6)
= 59.535 ÷ 2.4
= 24.80625 N ≈ 24.81 N
Weight of bar(W) = M * g = 2.7 * 9.8 = 26.46 N
Weight of monkey(w) = m * g = 1.35 * 9.8 = 13.23 N
Using sum of equilibrium in the vertical direction, we have:
+
= W + w ------- Eqn 1
Substituting T2, W & w into the Eqn 1
+ 24.81 = 26.46 + 13.23
= <u>14.88</u> N
<u>Answer: </u>
<em>Considering the II law of thermodynamics</em>
<em>From the figure</em>
<em>Out put of energy: </em>
Heat supplied from the source/ reservoir (Q₁) - Heat rejected to the surroundings from the system (Q) = Q₁ - Q₂. Also known as Net work done on the system.
<em>Input of energy: </em>
Amount of heat energy supplied to the system from the source (Q₁ ).
Efficiency (H.E) = η = Output÷ Input
η = (Q₁ - Q₂) ÷ Q₁
OR η = Wnet ÷ Q₁ ; since Wnet = (Q₁ - Q₂)
By definition, the mechanical advantage is the relationship that exists between the output force or load lifted and the value of the force applied.
Thus, using the definition, we have that the mechanical advantage is given by:

Therefore, the mechanical advantage of lifting the box by using a pulley is equal to 1.
Answer:
The mechanical advantage in this situation is:
Equal to 1