Calculating Mass, Force, and Acceleration of a Car

[xdeanna]

Each of the four wheels of a car pushes on the road with a force of 4.0 x 10³ N [down]. The driving force on the car is 8.0 x 10³ N [W]. The frictional resistance on the car is 6.0 x 10³ N [E]. Calculate the following:
(a) mass of the car
(b) net force on the car
(c) car's acceleration

For Fnet, would u also add 4(4.0 x 10³ N [up]) to the rest of vectors to cancel out the force all the tires have on the road? Or:
8.0 x 10³ N [W] + 6.0 x 10³ N [E]= 2.0 x 10³ N [W]

2.0 x 10³ N [W] + 4(4.0 x 10³ N [down])= Fnet
?!

I just did all that on my phone.. I'm desperate for some help :(

 

[rock.freak667]

Each of the four wheels of a car pushes on the road with a force of 4.0 x 10³ N [down]. The driving force on the car is 8.0 x 10³ N [W]. The frictional resistance on the car is 6.0 x 10³ N [E]. Calculate the following:
(a) mass of the car
(b) net force on the car
(c) car's acceleration

For Fnet, would u also add 4(4.0 x 10³ N [up]) to the rest of vectors to cancel out the force all the tires have on the road? Or:
8.0 x 10³ N [W] + 6.0 x 10³ N [E]= 2.0 x 10³ N [W]

2.0 x 10³ N [W] + 4(4.0 x 10³ N [down])= Fnet
?!

I just did all that on my phone.. I'm desperate for some help :(

I am led to believe that the entire mass of the car is supported by the wheels alone.

So yes the entire weight is 4(4x10³) N, so the mass of the car is ?

 

[xdeanna]

I am led to believe that the entire mass of the car is supported by the wheels alone.

So yes the entire weight is 4(4x10³) N, so the mass of the car is ?

m= 1.6 x 10⁴ N

but what about F_net

 

[rock.freak667]

m= 1.6 x 10⁴ N

but what about F_net

There is a driving force and a resistance to the driving force, so what should be the net force between these two?

 

[xdeanna]

There is a driving force and a resistance to the driving force, so what should be the net force between these two?

so i don't have to worry about the force of the tires on the road?

F_net=8.0 x 10³ N [W] + 6.0 x 10³ N [E]
F_net= 2.0 x 10³ N [W]

 

[rock.freak667]

so i don't have to worry about the force of the tires on the road?

F_net=8.0 x 10³ N [W] - 6.0 x 10³ N [E]
F_net= 2.0 x 10³ N [W]

you mean negative here


But yes that should be correct.