The first: alright, first: you draw the person in the elevator, then draw a red arrow, pointing downwards, beginning from his center of mass. This arrow is representing the gravitational force, Fg.
You can always calculate this right away, if you know his mass, by multiplying his weight in kg by the gravitational constant

let's do it for this case:

the unit of your fg will be in Newton [N]
so, first step solved, Fg is 637.65N
Fg is a field force by the way, and at the same time, the elevator is pushing up on him with 637.65N, so you draw another arrow pointing upwards, ending at the tip of the downwards arrow.
now let's calculate the force of the elevator

so you draw another arrow which is pointing downwards on him, because the elevator is accelating him upwards, making him heavier
the elevator force in this case is a contact force, because it only comes to existence while the two are touching, while Fg is the same everywhere
<u>Order sequence of steps that are involved in the production of work by a four-stroke heat engine as follows:
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- Piston moves down, allowing fuel-air mixture to enter intake valve
- Piston moves up, compressing gas and causing gas to increase its temperature
- Combustion as gas is still compressed; increase in energy from combustion pushes piston down
- Piston moves up, pushing burned gases through exhaust valve: Spark plug fires, causing
Answer: Options D, A, C and B
<u>Explanation:
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There are four basic steps of a four stroke engine- Intake, Combustion, Power and Exhaust. The first step is the intake of air plus fuel mixture in the combustion chamber. At this time, the piston moves down. Now when the chamber is closed, the spark plug ignites fire which expands the fuel gases.
The gases push down, piston and crankshaft rotates in this way. Once the gases the combustion is done, there is plenty of space in the chamber that makes the piston moves up. In this way a complete cycle is completed and the crankshaft moves. That’s the working of this four stroke engines.
Answer:
is there suppose to be a pic?
Explanation:
You’re correct hope this helps :)