[填空题]
A loaf pan is made in the shape of aj3x,c a .ucuw; cylinder. The7haj r/),ujva pan has a diameter of 24 cm and a h/hj r,ua jv)a7eight of 5 m.
1. Calculate the volume of this pan.
Gloria prepares enough bread dough to exactly fill the pan. The dough was in the shape of a sphere.≈ $cm ^3$
2. Find the radius of the sphere in $\mathrm{cm}$ , correct to one decimal place.
The bread was cooked in a hot oven. Once taken out of the oven, the bread was left in the kitchen. The temperature, T , of the bread, in degrees Celsius, ${ }^{\circ} \mathrm{C}$ , can be modelled by the function
$T(t)=a \times(1.51)^{-\frac{t}{3}}+21, \quad t \geq 0$,
where a is a constant and t is the time, in minutes, since the bread was taken out of the oven. When the bread was taken out of the oven its temperature was 205^{\circ} \mathrm{C} .≈ cm
3. Find the value of a .
4. Find the temperature that the bread will be 10 minutes after it is taken out of the oven.
The bread can be eaten once its temperature drops to 35^{\circ} \mathrm{C} .≈ $C^{\circ}$
5. Calculate, to the nearest minute, the time since the bread was taken out of the oven until it can be eaten.
6. In the context of this model, state what the value of 21 represents.≈
