Answer:
a) 
b) 
Explanation:
The law of conservation of mechanical energy states that total mechanical energy remains constant during oscillation. Mechanical energy is defined as the sum of kinetic energy and potential energy:

a) The position is one-third the amplitude. So, we have
. Replacing and solving for K

b) The potential energy is defined as:

Replacing:

Answer:
Coefficient of dynamic friction= md= 0.09931
Explanation:
To determine the coefficient of dynamic friction we must first match the friction force that is permendicular to the normal force of the block and opposite to the drag force, to the component of the drag force in this same direction. This component on the X axis of the drag force will be:
F= 90N × cos(30°) = 77.9423N
This component on the X axis of the drag force must be equal to the dynamic friction force that is equal to the coefficient of dynamic friction by the normal force of the block weight:
F= md × m × g= 77.9423N
m= mass of the block
md= coefficient of dynamic friction
g= gravity acceleration
F= md × 80kg× 9.81 (m/s²)= 77.9423(kg×m/s²)
md= (77.9423(kg×m/s²) / 784.8 (kg×m/s²)) = 0.09931
Answer:


Explanation:
The collision is elastic so we can use the conservation of momentum


Describe the motion in axis x'



Describe the motion in axis y'


Answer:
The answer to your question is: d = 0 m, it does not move
Explanation:
Data
vo = 20 m/s
a = -1 m/s2
t = 40 s
d = ?
Formula
d = vot + (1/2)at²
Substitution
d = (20)(40) + (1/2)(-1)(40)²
d = 800 - 800
d = 0 m It suggest that it does not move.
I hope it can help you