Answer:
The height of the ball when it hits t = 3 seconds will be 42 feet.
Explanation:
The user above me provides a very helpful explanation, so I am only writing this in his/her/their honor for his/her/their work :D
h = -16t² + 60t + 6
h = (-16)(3 s)² + (60)(3) + 6 = 42
nebular, i did it and its correct
B) because the air pressure is significantly higher when it is colder
C) because the molecules in the balloon have slowed down with the temperature
D) because the molecules shrink in size when exposed to the colder, outside air
Answer: Option (C) is the correct answer.
Explanation:
When the balloon was placed inside Tamika's classroom then the temperature was high as compared to the temperature outside the classroom.
As a result, gas molecules were in rapid motion but when balloon was placed outside the classroom then due to cold, there was decrease in temperature.
Therefore, the movement of gas molecules will slow down and the molecules will come slightly close to each other.
Hence, there will be shrinkage in the size of balloon.
Thus, we can conclude that the balloon has gotten a little bit smaller because the molecules in the balloon have slowed down with the temperature.
A) The temperature at the fat-inner fur boundary be so that the bear loses heat at a rate of 51.4W is; T_i = 38.52°C
B) The thickness of the layer contained within the fur so that the bear loses heat at a rate of 51.4 W is; t = 13.41 cm
We are given;
Diameter of sphere; d = 1.6 m
Radius of sphere; r = d/2
r = 1.6/2
r = 0.8 m
Thickness of bear; t = 3.9 cm cm = 0.039 m
Outer surface Temperature of fur; T_h = 2.8 ∘C
Inner surface Temperature of fat;T_f = 30.9 ∘C
Thermal conductivity of fat; K_f = 0.2 W/m⋅k
Thermal conductivity of air; K_a = 0.024 W/m⋅k
A) To find the temperature at the fat-inner fur boundary when heat loss is 51.4 W, we will use the heat current formula;
H = K_f•A(T_f - T_i)/t
Where;
A is area = 4πr²
A = 4π × 0.8²
A = 8.04 m²
T_i is the temperature we are looking for
H is heat loss = 51.4
t is thickness
Making T_i the subject gives;
T_i = (T_f × H × t)/(K_f × A)
T_i = (30.9 × 51.4 × 0.039)/(0.2 × 8.04)
T_i = 38.52°C
B) We want to find the thickness of the layer contained within the fur. Thus, we will use K_a instead of K_f. Let us make t the subject in the heat current formula to get;
t = (K_a•A(T_i - T_h)/H
t = (0.024 × 8.04 × (38.52 - 2.8))/51.4
t = 0.1341 m
t = 13.41 cm
Read more at; brainly.com/question/14548124
Answer:
Explanation:
Using the equation
H = Q/t = k A ( T hot - T cold) / L
where H is the rate of heat loss = 51.4 W, T cold be temperature of the outer surface, A is the surface area of the fat layer which is a model of sphere ( surface area of a sphere ) = 4πr² where diameter = 1.60 m
radius = 1.60 m / 2 = 0.80 m
A = 4 × 3.142 × ( 0.8²) = 8.04352 m²
making T cold subject of the formula
T cold = T hot - = 30.9° C - ( 51.4 W × 3.9 × 10⁻² m) / ( 0.2 W/mK × 8.04352 m² ) = 30.9° C - 1.25 ° C = 29.65° C
b) The thickness of air layer for the bear to lose heat t a rate of 51.4 W
thermal conductivity of air is 0.024 W/mK and rearranging the earlier formula
L = = (0.024 W/ m K × 8.04352 m²) ( 29.65° C - 2.8°C) / 51.4 W = 0.101 m = 10.1 m