Astudent 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. what is the most likely cause of the large percent error?

The acceleration of the plastic balls is not uniform.

Explanation:

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. What is the most likely cause of the large percent error?

from the kinematic equation

s=ut+

s=3m

a=9.8m/s^2

t=?

substituting into the equation

3=0*t+0.5*9.8t^2

t^2=.6122

t=0.782secs

if it is found to be 35% greater , then it will be

1.35*0.782

1.056s

the only casue would have been that

the downward acceleration of the ball is not uniform

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s