Contact forces has to be touching for it to be an actual force. A field force does not have to be touching but it does have to be acting on particles at different positions in a space.
Answer:106560 N
Explanation:
Given
Let Tension between 2 and 3 car be 
and between 3 &4 is 
mass of freight car =37,000 kg
acceleration of car
is accelerating all freights behind 3
therefore
Thus
Explanation:
Move the decimal point until it is behind the first non-zero digit.
In this case, we move it 3 places to the right so it is behind the 9.
Therefore, 0.0097 = 9.7×10⁻³.
