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Unformatted text preview: accelerate? How do they respond to a gravitational force?
5 Spring 2008 UCSD Physics 10 A Logical Argument
Consider two identical falling objects Now imagine two more, connected together with a tiny thread Mass of each = M Total Mass = 2 M But they all have the same acceleration! Force on the joined balls must be twice the force on one of them, since the mass doubled but the acceleration stayed the same. Conclusion: Gravitational force must be proportional to mass Spring 2008 6 UCSD Physics 10 Spring 2008 7 UCSD Physics 10 How Do We Know the Accelerations are the Same?
Experimental tests show the Universality of Free Fall is the same for different materials to within 0.00000000001% Spring 2008 8 UCSD Physics 10 Force Exerted by Gravity
If the gravitationally induced acceleration is the same for all objects at the surface of the Earth, then
Force exerted by gravity = (mass) (acceleration due to gravity) Fgravity = m g = WEIGHT, where g = 9.8 m/s2 For a mass of 100 kg, force from gravity at E...
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