348.34 m/s. When Superman reaches the train, his final velocity will be 348.34 m/s.
To solve this problem, we are going to use the kinematics equations for constant aceleration. The key for this problem are the equations 
and 
where 
is distance, 
is the initial velocity, 
is the final velocity, 
is time, and 
is aceleration.
Superman's initial velocity is 
, and he will have to cover a distance d = 850m in a time t = 4.22s. Since we know , and , we have to find the aceleration in order to find .
From the equation we have to clear , getting the equation as follows: 
.
Substituting the values:
To find we use the equation .
Substituting the values:
Answer:
-0.0789 m
Explanation:
Recall that the y-component comes associated with the sin(18.4) through the following trigonometric relationship:
y = 0.250 sin(-18.4) ≈ -0.0789 m
Notice it is negative since it is below the x-axis.
Answer:
Electromagnetic force
Explanation:
There are four fundamental forces in nature:
- Gravity: it is the force that is exerted between any objects with mass. It is the weakest of all forces, so it is only relevant at planetary scales. It is always attractive, and it has an infinite range.
- Electromagnetic force: it is the force exerted between charged objects and between magnets (it is responsible for electric fields and magnetic fields). It is the 2nd strongest force, and it is the force that holds atoms in a molecule together. It can be attractive or repulsive, and it has an infinite range.
- Strong nuclear force: it is the strongest of all forces. It is responsible for holding the nucleons together inside the nucleus, and it is attractive. It has a very limited range (
), so it is relevant only at very small scales
- Weak nuclear force: it is the force responsible for radioactive decays and neutrino interactions. It also has a very short range (
Looking at all these definitions, we see that the term that defines the force that acts between charged particles is the electromagnetic force.
