Answer:
Average speed = 46.67 m/s
Explanation:
Given that the time taken in covering first 1000 m = 25 seconds.
The time taken in covering next 2.5 km = 50 seconds.
Total distance covered = 1000 m + 2500 m = 3500 m
Total time taken = 25+50=75 seconds
Average speed = Total distance covered / total time taken
= 3500/75 = 46.67 m/s
Conservation of momentum: total momentum before = total momentum after
Momentum = mass x velocity
So before the collision:
4kg x 8m/s = 32
1kg x 0m/s = 0
32+0=32
Therefore after the collision
4kg x 4.8m/s = 19.2
1kg x βm/s = β
19.2 + β = 32
Therefore β = 12.8 m/s
Answer:
Water
Explanation:
windmills were used to bring water to farms in ancient times.
Answer: C
Explanation: Amplitude controls loudness, and frequency controls pitch. The more frequent the higher pitch.