Answer:
b 16 m/s².
Explanation:
Hello.
In this case, the force exerted to the mass of 400 kg at an acceleration of 4 m/s² is:
[tex]F=400kg*4m/s^2=1600N[/tex]
Now, since the mass is decreased to 100 kg (1/4 of 400 kg), and the force remain the same, the new acceleration should be:
[tex]a=\frac{F}{m}=\frac{1600kg*m/s^2}{100kg}\\ \\a=16m/s^2[/tex]
Thus, the answer is b 16 m/s².
Best regards.