How to calculate gravity?

Question

Ok so im doing a lab in physics where we drop pennies and i need to calculate gravity so here is all the info i have:

Mass of Penny: 2.4g

Distance to ground: 1143cm

Average time to hit ground: 1.76seconds

Answer 1

Xi = at^2 x (0.5)



no need the mass of penny for gravity



so the answer will be ;



11,43 = (0,5) a x 1,76^2



a= 7,37 m/s^2 whic is equal to gravity.

Answer 2

9.8 m/s is the approximate acceleration due to gravity on bodies near the surface of the Earth, not the gravitational force on those bodies. You can relate these quantities using the elementary Newtonian equation force = mass * acceleration ( F= ma). When you set up this equality, (m1*m2*G/r^2 = m1*a, where m1 is your mass, m2 is the mass of the earth, etc), you'll see that m1 (your mass) cancels out and you're left with m2*G/r^2, an equation for the acceleration. If you plug in those same numbers (depending on how many decimals you use), you'll get an answer very close to 9.8 m/s.

Answer 3

Gravity is equivalent to acceleration as Einstein pointed out, so find the acceleration and you have the value for gravity.



ps. The mass of the penny is not really relevant as Galileo pointed out

Answer 4

Start with formula D = a*t*t / 2 or 1/2 * a * t (squared)

11.43 = a * (1.76 * 1.76) / 2

a = 11.43 / 1.549

a = 7.38 m/sec./sec.