B. In the system of the object and the earth, by Newton's third law, the object will exert and equal and opposite force upon the earth.
Answer:

Explanation:
The energy lost due to air friction is equal to the mechanical energy lost by the parachutist during the fall.
The initial mechanical energy of the parachutist (at the top) is equal to his gravitational potential energy:

where
m = 20.1 kg is his mass
is the acceleration due to gravity
h = 662 m is the initial heigth
The final mechanical energy (at the bottom) is equal to his kinetic energy:

where
v = 7.12 m/s is the final speed of the parachutist
Therefore, the energy lost due to air friction is:

Answer:
<em>6.77m/s</em>
Explanation:
Using the law of conservation of momentum
m1u1 + m2u2 = (m1+m2)v
m1 and m2 are the masses of the object
u1 and u2 are the velocities before collision
v is the final collision
Given
m1 = 300g = 0.3kg
u1 = 6.0m/s
m2 = 10g = 0.01kg
u2 = 30m/s
Required
The bird's speed immediately after swallowing v
Substitute the given values into the formula
m1u1 + m2u2 = (m1+m2)v
0.3(6) + 0.01(30) = (0.3+0.01)v
1.8+0.3 = 0.31v
2.1 = 0.31v
v = 2.1/0.31
<em>v = 6.77m/s</em>
<em>Hence the bird's speed immediately after swallowing is 6.77m/s</em>
Answer:
Well my good friend the other person did not give U a good answer, it is actually the third one
Explanation: well it is the most logical of all the answers if you think about it and a lot of the creatures we have in the water today are thought of to have once lived on land based on the fossils we still find to this very day my friend
Answer:
Explanation:
Given
Force applied 
Door is
wide
for gate to revolve Properly Pivot Point must be at center i.e. 1.5 from either end
Torque applied is
Maximum torque


