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A student is testing the kinematic equations for uniformly accelerated motion by measuring the time it takes for light-weight plastic balls to fall to the floor from a height of 3 m in the lab. The student predicts the time to fall using g as 9.80 m/s2 but finds the measured time to be 35% greater. Which of the following is the most likely cause of the large percent error(A) The acceleration due to gravity is 70% greater than 9.80 m/s2 at this location.
(B) The acceleration due to gravity is 70% less than 9.80 m/s2 at this location.
(C) Air resistance increases the acceleration in the y direction.
(D) The acceleration of the plastic balls is not uniform.

Respuesta :

The most possible cause of 35% increase in time measured is due to the acceleration due to gravity which is 70% less than 9.80 m/s² at this location.

Explanation:

We know that for a linear motion

S=ut+(1/2)*a*t²

Where S= Distance covered

u= initial velocity

t=time period

a= acceleration due to gravity

Since the body is falling vertically downwards "a" is to be replaced by "g"

Moreover, The body is falling from rest "u"=0

Hence the equation reduces to S=1/2*g*t²

t²=2S/g

Since the "g" is in denominator thus a decreased value of "g" would mean increased period. Thus an increase of 35% in the period would translate to a 70% decrease in "g".