Answer:
5850N
Step-by-step explanation:
Given parameters: 
Mass of the car = 750kg 
Acceleration = 7.8m/s² 
Unknown: 
Net force = ? 
Solution: 
According to Newton's second law of motion; 
 Force = mass x acceleration 
To find the net force input the given parameters: 
 Net force on the car = 750 x 7.8 = 5850N