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%.
Answer:

Explanation:
<u>Vertical Launch Upwards</u>
In a vertical launch upwards, an object is launched vertically up from a height H without taking into consideration any kind of friction with the air.
If vo is the initial speed and g is the acceleration of gravity, the maximum height reached by the object is given by:

The object referred to in the question is thrown from a height H=0 and the maximum height is hm=77.5 m.
(a)
To find the initial speed we solve for vo:



(b)
The maximum time or the time taken by the object to reach its highest point is calculated as follows:



Answer:
An insulator holds charge within its atomic structure. Objects with like charges repel each other, while those with unlike charges attract each other. A conducting object is said to be grounded if it is connected to the Earth through a conductor.
Explanation:
Source:https://courses.lumenlearning.com/physics/chapter/18-2-conductors-and-insulators/
Answer:
1716.75 J
Explanation:
<u>Step </u><u>1</u><u>:</u> First check what we are provided with. As per given question we have:
mass (m) = 70 kg, height (h) = 2.5 m and acceleration due to gravity (g) = 9.81 m/s².
<u>Step</u><u> </u><u>2</u><u>:</u> Check what we are asked to find out.
Work done = Change in Potential energy
The stuff required to solve this question is potential energy. Using the formula: P = mgh. Where P is Potential energy, m is mass, g is acceleration due to gravity and h is height.
<u>Step</u><u> </u><u>3</u><u>:</u> Substitute the known values in the above formula.
→ P = 70 × 2.5 × 9.81
→ P = 1716.75 J
Hence, the work done against the force of gravity is 1716.75 J.