Answer:
Reflection involves a change in direction of waves when they bounce off a barrier. Refraction of waves involves a change in the direction of waves as they pass from one medium to another.
Answer
given,
diameter of the pipe is = (14 ft)4.27 m
minimum speed of the skater must have at very top = ?
At the topmost point of the pipe the normal force will be equal to zero.
F = mg
centripetal force acting on the skateboard

equating both the force equation


r = d/2 = 14/ 2 = 7 ft
or
r = 4.27/2 = 2.135 m
g = 32 ft/s² or g = 9.8 m/s²

v = 14.96 ft/s
or

v = 4.57 m/s
The toxic runoff from the farms will directly enters the water bodies of the earth through the drainage system.
The emissions from the cars will go into atmosphere and will react with water and then it will enter the earth's water. So, it is not directly affecting the earth's water.
The dumping trash on roadsides do not enter the earth's water. It can enter the earth's water through rains.
The production of oxygen by trees is not pollution.
Hence, option (A) is correct.
Answer:
Answer: It allows people to rapidly heat items
Hope this helps!
Explanation:
Answer: 490N
Explanation:
Newton is the unit for force. Force = mass x acceleration
F=N m=50kg a=9.8 (earth's acceleration of gravity)
F=50X9.8
F≈490N