# Science ~conversions~

posted by .

On my physics home work i have a question that puts the weight in grams, and i need to find the acceleration. I know that the formula is F=ma, and Force is in newtons, mass is in kg and acceleration is in m/s^2. but can you still find the acceleration by using grams with out converting? because when a converted the mass (1.5g) to kg (.0015kg) and then put it throught the equation the answer didn't fit with the problem.

the problem is asking the acceleration of a bug (1.5g) when a spider pulls it by a massless spider silk with .001N.

when i put in the formula without converting i get .0073m/s^2. which seems plausible.

but when i convert i get 7.3m/s^2. which would make a VERY fast spider....

so i guess my question is just:
do you HAVE to convert in order to get the correct answer

• Science ~conversions~ -

oops. correction. the spider is pulling with .011N. NOT .001

• Science ~conversions~ -

Maggie, you on the right way but I don't understand how did you get both the values.
The solution is
a = F/m = 1*10^(-3)/1.5*10^(-3)= 1/1.5 = (2/3) m/s^2 = 0.67 m/s^2.

• Science ~conversions~ -

Not a big deal:

a = 1.1*10^(-2)/1.5*10^(-3) =
= (1.1/1.5)*10 = 7.3 m/s^2

Good for a spider!

• Science ~conversions~ -

a= F/m=0.001/1.5•10⁻³=0.67 m/s²