heat = mass x spec heat x temp rise
40.5=15.4x10^-3xspec heatx11.2
Answer: Some challenges that I could see would be the walls, possibly a moat, tar, and the towers.
Explanation: The wall is obliviously a main problem, trying to get over it or through it is a difficult challenge. The moat (if it has one) means that there is more than likely only one way to get in or out. If it does have tar it means that the attackers are going to be put in a "sticky situation" And finally the towers, they have people at the top shooting arrows down at you, or throwing things at you.
Length of the cord..........................................................
Answer:
The time taken is 
Explanation:
From the question we are told that
The speed of first car is 
The speed of second car is 
The initial distance of separation is 
The distance covered by first car is mathematically represented as

Here
is the initial distance which is 0 m/s
and
is the final distance covered which is evaluated as
So


The distance covered by second car is mathematically represented as

Here
is the initial distance which is 119 m
and
is the final distance covered which is evaluated as

Given that the two car are now in the same position we have that


Answer:
B. 24.2 m/s
Explanation:
Given;
mass of the roller coaster, m = 450 kg
height of the roller coaster, h = 30 m
The maximum potential energy of the roller coaster due to its height is given by;



Therefore, the maximum speed of the roller coaster is 24.2 m/s.