Rolling down

Classical Mechanics Level 2

A railroad car is rolling down a steep hill of uniform slope with no friction, leaking a steady stream of sand.

If we take a snapshot photo, what would be the direction of the leaking sand?

Select the picture that best represents your answer.

1 2 3 4

Laszlo Mihaly by Laszlo Mihaly , 57, USA

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

1 solution

Laszlo Mihaly
Apr 5, 2018

The sand stream will be perpendicular to the tracks, choice 1 in the pictures.

If one considers the situation from a non-inertial frame of reference that moves together with the car, there will be an "inertial force" F = − m a F=-ma acting on all bodies, where a a is the acceleration of the car. Since there is no friction, a = g sin ⁡ α a=g \sin \alpha in the direction parallel to the tracks (here α \alpha is the angle of the slope relative to the horizontal). Therefore the gravitational force and the inertial force will add up to an effective gravitational force that is perpendicular to the tracks.

0 Helpful 0 Interesting 0 Brilliant 3 Confused

But according to the question, observation should be made from a reference frame attached to the ground. So option C would be more appropriate

Ash K - 1 month, 1 week ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...