Answer:
-4.5 m/s
Explanation:
Even without doing calculations, we know that a projectile has the same speed coming down as it did going up at the same height. Since it went up at 4.5 m/s, it returns down at -4.5 m/s.
To prove it with math, use the given information:
v₀ = 4.5 m/s
a = -9.8 m/s²
Δy = 0 m
Find: v
v² = v₀² + 2aΔy
v² = (4.5 m/s)² + 2 (-9.8 m/s²) (0 m)
v = -4.5 m/s
Answer: The color of a star plays a significant role in determining its age as well as its temperature. A star normally appears to be shining as we see through the atmosphere. An increase in the temperature of a star releases more energy and this can be observed in the various colors of color spectrum.
The hottest star generally appears to be bluish-white in color whereas the coldest star usually appears to be reddish in color.
Thus, a star's color can help us determining its temperature.
Answer:
92km
Explanation:
Given parameters:
Duration of the journey = 6hrs
Average speed = 58km/hr
Now, let us find the total distance of the journey;
Distance = Speed x time
Distance = 58 x 6 = 348km
So;
Average speed for the first 4hrs = 64km/hr
Time = 4hrs
Distance = 64 x 4 = 256km
For the rest of the journey, the student will cover;
= 348km - 256km
= 92km
Answer:
sawing a board in half
dissolving sugar in water
a block of ice subliming
Explanation:
Urbanization can cause a lot of problems for nature such as pollution, global warming, and depletion of wildlife such as plants and animals.