displacement of the plane is given as

time taken by the plane

now the velocity is given as



so the velocity of airplane is 399 mi/h towards South West
Answer:
The forces experienced by the middle particle are attractive, and the net force will remain the same (0) if and only if the distances of the sides particles to the middle particle are the same.
Explanation:
In example 20.3 the forces experienced by the middle particle are repulsive because all the particles are positive, for the case in which the particles on the sides are replaced for negative charge particles the forces experienced by the middle particle are attractive. Regarding the net force, because we don't know the distances we can not give a definitive answer, what we can say is that if the distances from the middle particle to the sides particles are the same the net force is zero for both cases (remain unchanged).
Answer:

Explanation:
Given that,
The mass of a Moon, 
The mass of the Earth, 
The moon's mean orbit distance around the earth is, 
We need to find the gravitational force exerted on the moon by the Earth.
The formula of gravitational force is given by :

So, the required force is
.
Answer:
zero
Explanation:
Work done = - 400 J
In an isothermal process, the temperature remains constant. So, according to the first law of thermodynamics
dQ = dU + dW
As the temperature remains constant and the change in internal energy is the function of change in temperature, here change is temperature is zero so the change in internal energy is also zero.
The reason you only see fossils in sedimentary rock is that these set of rocks are formed in much lower pressure and temperature, compared to the other types of rocks like igneous rocks.