Answer:
I couldn't find options for your question online, but I can give you an explanation so you can choose the correct option.
Explanation:
A spark knock is a form of unpredictable behavior that occurs in combustion, that is, in the chemical reaction that occurs between oxygen and an oxidizable material. Such combustion is usually manifested by incandescence or flame.
The spark knock is a detonation that occurs when there is a lot of pressure in the fuel.
<u>Some situations in which this can happen are:
</u>
- Engine overloaded.
- Maximum pressure in the cylinders.
- Engine overheated.
- Overheated air.
- Long and excessive engine ignition timing.
- Spark plug at high temperatures.
Answer:
The nail exerts a force of 573.88 Pounds on the Hammer in positive j direction.
Explanation:
Since we know that the force is the rate at which the momentum of an object changes.
Mathematically 
The momentum of any body is defines as 
In the above problem we see that the moumentum of the hammer is reduced to zero in 0.023 seconds thus the force on the hammer is calculated using the above relations as


Answer:
135 hour
Explanation:
It is given that a carburizing heat treatment of 15 hour will raise the carbon concentration by 0.35 wt% at a point of 2 mm from the surface.
We have to find the time necessary to achieve the same concentration at a 6 mm position.
we know that
where x is distance and t is time .As the temperature is constant so D will be also constant
So
then
we have given
and we have to find
putting all these value in equation

so
Answer: c) 450 kPa
Explanation:
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
(At constant temperature and number of moles)
where,
= initial pressure of gas = 150 kPa
= final pressure of gas = ?
= initial volume of gas = v L
= final volume of gas =
Therefore, the new pressure of the gas will be 450 kPa.