All of the above.
if your car is on a steep hill it needs force to stop moving and to speed up
Answer:
F₁ = 4,120.2 N
F₂ = 3,924N
Explanation:
1) Balance of angular momentum around the end where F₁ is applied.
F₂ × 0.5m - F₁ × 0 = mass × g × 1m
⇒ F2 × 0.5 m= 20 kg × 9.81 m/s² × 1 m = 1,962 N×m
F₂ = 196.2 Nm / 0.5m = 3,924 N
2) Balance of forces
F₁ - F₂ = mg
F₁ = F₂ + mg = 3,924N + 20kg (9.81 m/s²) = 4,120.2 N
I think it is D- diluting a solution sorry if i am wrong
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.
