There are three things we can do to improve the environment in our school. First, we should clean up all areas regularly. For example, we can organise clean-up activities at weekends. By doing this, we can keep our environment clean, beautiful, and safe for everyone. Secondly, we should plant more trees and flowers around the school yard to create more shade and fresh air. Finally, we can place recycling bins in the hallways to encourage students to sort plastic waste. In conclusion, we can improve the environment in our school in many ways and even small actions can make a big difference.

a)

lực kéo=800N

công=36000J

công suất=2400W

b)

lực kéo=1800N

công=81100J

công suất=5400W

khối lượng=0,5kg

vận tốc tại độ cao=9,49m/s