To increase the potential energy of any object, not limited to an apple, you have to hold it higher.
1. I think a drum would be the easiest instrument to explain. You can vary the pitch and loudness by hitting it with different intensities or at different points or angles.
PS. I'm not talking about a drumset. I'm talking about an ordinary drum.
2. Different types of instruments sound different even though they play the same notes because they use different mechanisms for producing sound.
Answer:
No, the farmer is not able to move the mule.
Explanation:
Mass =100 kg
Force=F=800 N
The coefficient between the mule and the ground=

Static friction force,f=
Normal force=N=mg
Static friction force,f=
Using 
F<f
Static friction force is greater than applied force.
Therefore , the farmer is not able to move the mule.
Answer:
m = 3.91 kg
Explanation:
Given that,
Mass of the object, m = 3.74 kg
Stretching in the spring, x = 0.0161 m
The frequency of vibration, f = 3.84 Hz
When the object is suspended, the gravitational force is balanced by the spring force as :



k = 2276.52 N/m
The frequency of vibration is given by :



m = 3.91 kg
So, the mass of the object is 3.91 kg. Hence, this is the required solution.
Answer:
0.51 m
Explanation:
Using the principle of conservation of energy, change in potential energy equals to the change in kinetic energy of the spring.
Kinetic energy, KE=½kx²
Where k is spring constant and x is the compression of spring
Potential energy, PE=mgh
Where g is acceleration due to gravity, h is height and m is mass
Equating KE=PE
mgh=½kx²
Making x the subject of formula

Substituting 9.81 m/s² for g, 1300 kg for m, 10m for h and 1000000 for k then
