# Please explain in details how to get the answers for problems below.

Problem 1:

A box is sliding down a plane inclined at an angle of 20 degrees from the horizontal. Find the acceleration of the box, neglecting friction and air resistance.

Possible answers:

(1) 0.342 m^2g

(2) 0.342 m

(3) 0.342 g

(4) 0.342 mg

(5) 0.940 m^2g

(6) 0.940 m

(7) 0.940 g

(8) 0.940 mg

Problem 2:

A box that is hurled up the inclined plane of the above Problem 1, starts up the plane with an initial velocity of 1,000 cm/sec. Find the speed of the box moving up the plane 3 sec later.

Possible answers:

(1) 0 cm/sec

(2) -5.5 cm/sec

(3) 8.9 cm/sec

(4) 10.1 cm/sec

(5) 42.5 cm/sec

(6) 63.3 cm/sec

(7) 75.3 cm/sec

(8) 98.1 cm/sec.

https://brainmass.com/physics/resistance/spped-box-neglecting-friction-air-resistance-539772

#### Solution Preview

For the first question, you must first draw a free body diagram very similar to this one:

http://physics.bu.edu/~duffy/semester1/c5_incline.html

The force which moves the box, in that diagram, is mgx. This force can be represented via trigonomic relationships with the force of gravity (mg) itself:

sin theta = mgx / mg

In our case, our ...

#### Solution Summary

The solution finds the acceleration of the box, neglecting friction and air resistance. It also assists with drawing a free body diagram.