Change in position of object = Displacment
Example of surface events are erosion and weathering. Erosion is the carrying of a particle from one place to the other and weathering is the breaking down of particles. These processes help in rock formation because this allows physical changes (grouping together or breaking down) on a certain substance. Subsurface events are those which happened underground such as the flow of underground water which subsequently allow the deposition of minerals, etc.
Answer:
1. 218.55 N
2. 
3. 
Explanation:
Part 1;
Net force 
where m is mass, g is gravitational force and 
is the angle of inclination
Frictional force, 
is given by
where 
is the coefficient of static friction
Since 
, therefore, the block doesn’t slip and the frictional force acting is mgh=218.55N
Part 2.
Using the relationship that
Frictional force 
The maximum angle of inclination 
Part 3:
Net force on the object is given by
where 
is the coefficient of kinetic friction
= 9.8 ( sin 38 - (0.51) cos 38 )
= 
You didn't actually include the speed of sound. But it doesn't matter for this question. If the trumpeter and the listener are on the same moving sidewalk then the distance between them is not changing. The Doppler shift only happens when the distance between the source and the Observer is changing. So the Listener hears the same 290 Hertz that the trumpeter is generating.
