Hellow!
First, lets recabe information:
m (mass) = 1500 kg
a (aceleration) = 3 m/s²
F (Force) = ?
For calculate Force, if we have mass and aceleration, we can applicate the second law of Newton:
"Force is proportional to the product of the mass plus aceleration."
In a equation, this is like:
F = m * a
Let's replace according we information, and let's resolve:
F = 1500 kg * 3 m/s²
F = 4500 N
Result:
The force applicated is of 4500 Newtons.
Gud Luck!