A 10 kg block is pulled across a table by a force of 42 N with an opposing force of 6 N due to friction. What is the acceleration of the block?

Given:

M=10KG

F=42N

Opposing Force=6N

If we can recall F=ma, we can easily calculate the acceleration by substituting the given variables; but in our case, we have an opposing force. So we have to subtract the opposing force from the horizontal force.

F = ma

42N-8N=10KG x a

34N = 5KG x a; divide both sides by 10KG for a to be sole variable

34kg m/s^2) / 10kg x a (Newtons are sometimes referred to as kg m/s^2)

3.4 m/s^2 = a ; (kg's are cancelled)

Therefor, our acceleration is 3.4 m/s^2.

some think that theories become laws, but theories and laws have separate and distinct roles in the scientific method. a law is a description of an observed phenomenon in the natural world that hold true every time it is tested. it doesn't explain why something is true; it just states that it is true.

a.   mass number from atomic number