Abox slides down a frictionless plane inclined at an angle θ ¸ above the horizontal. the gravitational force on the box is directeda)vertically. b)perpendicular to the plane. c)at an angle θ ¸ below the inclined plane. d)parallel to the plane in the same direction as the movement of the box. e)parallel to the plane in the opposite direction as the movement of the box.

If we draw the Free Body Diagram for this situation (figure attached), taking into account only the gravity force in this case, we will see the weight of the block, which is directly proportional to the gravity acceleration :  

This force is directed vertically at an angle below the inclined plane, this means it has an X-component and a Y-component:

Therefore the correct option is c

Explanation:

When a box is placed in the friction less plane inclined at an angle θ. The forces acting on the box are

1. Weight of the box, W = m g

2. Force of friction, f

3. Normal force, N

When we resolve these forces in horizontal and vertical components, we get :

We know that the direction of gravitational force is always in downward direction. So, the gravitational force on the box is directed vertically. Hence, the correct option is (a).

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.