A moving company needs to load boxes in the truck. Which simple machine would be the best choice to help move the heavy boxes?

Inclined plane
lever
puller
wedge

The Lever

Explanation:

The lever is the most appropriate, as the loads can be placed at the short-distance end of the beam, while in long end the force is applied, this force is multiplied by the long arm of the lever. This raises the load to the level of the truck platform.

In the attached image we can see a graphic with the definition of the working principle of the lever.

where are the vectors ?

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