That thing is used as a lever.
Answer:
a. 960 W b. One 1 kW room heater
Explanation:
a. The rate of heat conduction P = kA(T₂ - T₁)/d where k = 2 × 0.040 W/m-K = 0.080 W/m-K since the thermal conductivity of glass wool is 0.040 W/m-K and that of the material is twice the thermal conductivity of glass wool, A = area of walls = 120 m², T₁ = outside surface temperature = 5.0 °C, T₂ = inside surface temperature = 18.0 °C and d = thickness of wall = 13.0 cm = 0.13 m
P = kA(T₂ - T₁)/d
= 0.080 W/m-K × 120 m²(18.0 °C - 5.0 °C)/0.13 m
= 9.6 Wm/K × 13 K/0.13 m
= 124.8 Wm/0.13 m
= 960 W
b. The number of 1 kW room heater required will be
n = rate of heat conduction/power of one room heater = 960 W/ 1 kW = 960 W/1000 W = 0.96 ≅ 1
So we need only one 1 kW room heater.
Answer:
D) 0.33 m/s² to the right
Explanation:
Apply Newton's second law. Take right to be positive and left to be negative.
∑F = ma
20 N − 5 N = (45 kg) a
a = 0.33 m/s²
The couch accelerates at 0.33 m/s² to the right.
The scientific notation of <span>1.574 E8 would be 4.69202787 * 10^3</span>
Answer:
F₀= 12 mg θ = 85.2º
Explanation:
When the force is applied the pendulum moves laterally, and the tension in the rope has components that reached a point balances the horizontal force. Let's apply make sure Newton
X axis
F -Tx = 0
F = Tx
Axis y
Ty -W = 0
Ty = W
Let's look for the tension components
cos θ = Ty / T
sin θ =Tx/T
Ty = T cos θ
Tx = T sin θ
Let's replace and solve the system of equations
F = T sin θ
mg = T cos θ
F / mg = tan θ
tan θ = 12 mg / mg
θ = tan -1 12
θ = 85.2º
