Answer:
The density of the block is 7.4g/ml.
Explanation:
We can determine the volume of the metal block by taking the difference between the volumes measured in the graduated cylinder:

Now, as we know that the average density of an object is calculated dividing its mass by its volume, we can calculate the density ρ of the metal block using the expression:

Finally, it means that the density of the metal block is 7.4g/ml.
Answer:
yi = Initial height of the helicopter
yf = final height of the helicopter
vyi = component of the initial vertical velocity of the helicopter
g = gravity constant (9.8m/s^2)
yf = yi + vyideltat - 1/2gt^2
0m = 1000m + (15m/2)deltat - 1/2(9.8m/s^2)t^2
-1000m = (15m/s)t - (-4.9m/s^2)t^2
Use the quadratic formula
4.8t^2 - 15t - 1000 = 0
t1 = 15.75s and t2 = -12.65
t2 is rejected, time can't be negative
Thus, it takes 15.75s before the package strikes the ground.
Answer:
Recessed incandescent luminaires not marked type ic and those marked for installing directly in insulated ceilings must not have insulation over the top of the luminaire.
Explanation:
Depending on how they interact with insulation, lighting fixtures are rated at various levels. Non-IC rated lighting fixtures can accommodate higher wattage bulbs, but they also pose the greatest fire risk when used with the incorrect insulation.
In locations with insulation, light fixtures that are not IC rated may be installed. But there is a condition. The distance between the fixture and any insulation should be 3 inches. But the 3 inch gap in the insulation would negate the goal of insulation by producing a lot of uninsulated space, so this defies logic. Building a box-style cover to cover the fixture on the attic side is one option to fix this. Drywall or foil-faced foam insulation can be used to create this box. After the cover is put in place, insulation can be added for maximum effectiveness.
To learn more about recessed incandescent luminaries. Click brainly.com/question/17218799
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