The equation below describes a physical situation:

\frac { 1 } { 2 } ( 1.70 \mathrm {~kg} ) \left( 3.30 \frac { \mathrm { m } } { \mathrm { s } } \right) ^ { 2 } + ( 1.70 \mathrm {~kg} ) \left( 9.80 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } } \right) ( 2.35 \mathrm {~m} ) \sin 30 ^ { \circ }

= \frac { 1 } { 2 } ( 1.70 \mathrm {~kg} ) \left( 4.60 \frac { \mathrm { m } } { \mathrm { s } } \right) ^ { 2 } + 0.320 ( 1.70 \mathrm {~kg} ) \left( 9.80 \frac { \mathrm { m } } { \mathrm { s } ^ { 2 } } \right) ( 2.35 \mathrm {~m} ) \cos 30 ^ { \circ }

Which description best fits the equation?
A)A 1.70 kg block slows down while sliding down a frictionless plane inclined at a 30

\degree

angle.
B)A 1.70 kg block slows down while sliding down a plane with

\mu

_k = 0.320,with the plane inclined at a 30

\degree

angle.
C)A 1.70 kg block speeds up while sliding up a frictionless plane inclined at a 30

\degree

angle.
D)A 1.70 kg block speeds up while sliding down a plane with

\mu

_k = 0.320,with the plane inclined at a 30

\degree

angle.
E)A 1.70 kg block slides over the top of an inclined plane and then descends on the other side.Both planes,inclined at a 30

\degree

angle,have

\mu

_k = 0.320.

A 20-Kg Block Slides Down a Plane (Inclined at 40 °\degree°

Multiple Choice