11th grade
posted by Anonymous .
What is the acceleration on planet X, if a 1.5 kg object weighs 3.45 N on plantet X?

Labeling the School Subjct "llth grade" may not get the teacher you need to read your post.
Sra 
Newton's Second Law:
F(or weight) = mass x acceleration.
so, a = F/mass = 3.45/1.5
You do the math and don't forget the units! 
2.3