9. A toy helicopter is 22 meters high as it flies at a velocity of 10 m/s, the helicopter's mass is 3 kg. Calculate the mechanical energy of the toy helicopter.

M. E=KE+PE

m. e =1/2mv2+mgh

PE=3X9.81X22

647.46

KE=1/2X3X10^2

150

KE+PE=647.46+150=797.46

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.