Answer:1.63 m
Explanation:
Given
mass of block 
inclination 
Amount of work done 
block slides a distance s along the Plane
Work done =change in Potential Energy
Increase in height of block is 
Change in Potential Energy 



Explanation:
Mechanical waves are waves that requires a medium for their propagation. There are two types of mechanical waves:
- Transverse waves
- Longitudinal waves
Transverse waves are waves that propagates perpendicularly to their source. Examples are electromagnetic waves, ripple on water etc.
Longitudinal waves are waves that propagates parallel to their source. They move in a series of rarefactions and compressions along their path. An example is seismic p-waves
Answer:
B
Explanation:
Friction always eventually stops whatever is in motion.
Efficiency or
is calculated by formula:
where
also efficiency has no unit.
Now put in the data and calculate the efficiency.

The efficiency of the machine is 0.8
If you want to get percentage just multiply by 100 and you get 80%
Hope this helps.
r3t40