Answer:
Explanation:
Given
Two masses
and
is released and there is tension T in the string
Suppose a is the acceleration of the system
Therefore from Diagram
For 

------1
for m_2 body

-------2
From above two Equation it is said that Tension is greater than m_1g and less than m_2g

Answer:
D. −F
Explanation:
the rest of the answers are
2/3F
The force is represented as a positive quantity and is repulsive.
Electrostatic force is inversely proportional to the square of the distance.
The direction of the force changes, and the magnitude of the force quadruples.
hope this helps sorry if i was too late! :)
Answer:

Explanation:
In this process energy must be conserved. On the initial stage, there will be only gravitational potential energy, while on the final stage there will be only elastic potential energy, so they will be equal. We write this as:

Which is the same as:

So we can obtain our mass from there, and for our values:

The total momentum of the system is preserved through the collision.
Note that momentum is
P = m*v
where m = mass
v = velocity.
Initial momentum:
P1 = (30000 kg)*(2 m/s) = 60000 (kg-m)/s for the moving car
P2 = 0 for the starionary car.
Final momentum:
P3 = (30000 + 30000)*v = 60000v (kg-m)/s
Because momentum is preserved,
P3 = P1 + P2
60000v = 60000
v = 1 m/s
The final velocity is 1 m/s.
Answer: 1.0 m/s