<span>A sheet of copper could cause the object to lose the most amount of heat. Copper is an essential element and a good conductor of heat. Heat can transfer from one end of a piece of copper to the other end.</span>
Answer:
Explanation:
Since the object is under a circular motion, according to Newton's second law, when the object is at the top of the circle we have:
Where 
is the centripetal force and is given by:
Replacing and solving for T:
Answer:
13.7%
Explanation:
Given that,
Heat absorbed by the engine = 97.2 kJ
Heat exhausted by the engine in each cycle = 83.8 kJ
We need to find the efficiency of the engine. It is calculated by the formula.
so, the efficiency of heat engine is 13.7%.
The answer is A. Friction
hope this helps :)
Answer:
Explanation:
a )
Reaction force of the ground
R = mg
= 160 N
Maximum friction force possible
= μ x R
= μ x 160
= .4 x 160
= 64 N .
b )
160 N will act at middle point . 740N will act at distance of 3 / 5 m from the wall ,
Taking moment about top point of ladder
160 x 1.5 + 740 x 3/5 + f x 4 = 900 x 3
240 + 444 + 4f = 2700
f = 504 N
c )
Let x be the required distance.
Taking moment about top point of ladder
160 x 1.5 + 740 x 3 x / 5 + .4 x 900 x 4 = 900 x 3 ( .4 x 900 is the maximum friction possible )
240 + 444 x + 1440 = 2700
x = 2.3 m
so man can go upto 2.3 at which maximum friction acts .
