An ideal spring is hung vertically from the ceiling. When a 2.0-kg mass hangs at rest from it, the spring extends 6.0 cm from its relaxed length. A downward external force is now applied to the mass to extend the spring an additional 10 cm. Find the work done by the spring force while the spring extension changes from 6.0 cm to 16 cm

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

causes

fossil fuels burn

cities become more industrialized

human population grows worldwide