Physics questions thread

[JuliaPascale123]

https://imgur.com/a/8rUw1 (question)
https://imgur.com/a/Z1oBO (Graph)

Could I please have some assistance with calculating the pressure, volume and temp of each of the four points. (question 2)

I already did Question 1 so the efficency of the diesel motor is:
https://imgur.com/a/uesqN


Notice: This is physics im just not sure how to find the values from what they have supplied

[Wren]

Need some help here. Not sure what I'm trying to find.
A fuel pump sends gasoline from a car's fuel tank to the engine at a rate of 7.81x10-2 kg/s. The density of the gasoline is 732 kg/m3, and the radius of the fuel line is 2.99x10-3 m. What is the speed at which gasoline moves through the fuel line?