If the objects comprise a gas, then the first object contains more
thermal energy (heat) than the second object.
If the objects are solid, then you can't draw any conclusion unless
both objects have the same total mass. If that's the case, then the
first object must be moving faster than the second one.
The contact force is indeed caused by "Contact".
Air resistance is basically a type of friction, which is apparently present providing two object contact.
The rest selections are all interaction force, which is not necessarily caused by contact.
Answer:443.1 s
Explanation:
Given
Engine of a locomotive exerts a force of 
Mass of train
Final speed (v)
F=ma
so 
and acceleration is
The steps in the heating of a metal seat in a park are:
Step 1: Heat travels from the sun to Earth
Step 2: Heat travels through atmosphere to the top of the seat
Step 3: Heat from the top of the seat travels through the seat to the lower parts of the seat.
-- Heat is transferred by radiation in Step 1 and Step 2. <em>(B)</em>
-- From the top of the seat to the bottom, heat is transferred by conduction.
There's no convection happening anywhere in the park-hot-seat scenario.
