Answer:

Explanation:
= Activation energy = 160 kJ
T = Temperature = 510 K
R = Universal gas constant = 8.314 J/mol K
The fraction of energy is given by

The fraction of energy is 
Answer:
Balancing of forces,
In the X-direction:
-Tcos4.5^o +Tcos4.5^o=0
In the Y-direction:
Tsin4.5^o +Tsin4.5^o-m*g=0
2Tsin4.5^o=15*9.81
T=(15*9.81)/(2sin4.5^o)
=937.75 N
Therefore, tension in the rope is 937.75 N.
For velocity vs time graphs, you can calculate displacement by finding the area between the line and the x-axis (time line). You should be able to recognize that space between the lines as a triangle, trapezoid, square, or rectangle and use the respective area formulas for these shapes.
See attached photo for worked out solution.
"2 km/hr/s" means that in each second, its engines can increase its speed by 2 km/hr.
If it keeps doing that for 30 seconds, its speed has increased by 60 km/hr.
On top of the initial speed of 20 km/hr, that's 80 km/hr at the end of the 30 seconds.
This whole discussion is of <em>speed</em>, not velocity. Surely, in high school physics,
you've learned the difference by now. There's no information in the question that
says anything about the train's <em>direction</em>, and it was wrong to mention velocity in
the question. This whole thing could have been taking place on a curved section
of track. If that were the case, it would have taken a team of ace engineers, cranking
their Curtas, to describe what was happening to the velocity. Better to just stick with
speed.