E=F*d/2 = M*g*d/2 = 25kg * 9.8 N/kg *0.65m / 2 = 79.625J
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:
Explanation:
Both graphs show plotted points forming a curved line. Curved lines have changing slope; they may start with a very small slope and begin curving sharply (either upwards or downwards) towards a large slope. In either case, the curved line of changing slope is a sign of accelerated motion (i.e., changing velocity).
Answer:
A & D
Explanation:
A single-displacement reaction is a chemical reaction whereby one element is substituted for another one in a compound and thereby generating a new element and also a new compound as products.
From the options, only options A & D fits this definition of single-displacement reactions.
For option D: Both left and hand and right hand sides each have one element and one compound. We can see that K is substituted from KBr to join Cl to form KCl and Br2 on the right hand side.
For option A: Both left and hand and right hand sides each have one element and one compound. We can see that OH is substituted from 2H2O to join Mg to form Mg(OH)2 and H2 on the right hand side.
The other options are not correct because they don't involve only and element and a compound on each side of the reaction.
<span>O + Na + Cl = NaClO
Reactants :
O -> </span><span>Oxygen
</span><span>
Na -> Sodium
Cl-> Chlorine
hope this helps!
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