151.9j
Explanation:
PE=1/2kx^2
PE=1/2(980)(.50)= 245j
PE=(1/2)(980)(.81)= 396.9j
396.9- 245= 151.9j
When the surface of a hard disk is scratched an some or all of the files are destroyed, it is called a head crash. It is a result of a disk in contact with the rotating platter causing it to permanently damage a very sensitive part of the disk.<span />
Answer:


Explanation:
Given:
- minimum amplitude at the start of oscillation cycle,

- the first maximum amplitude after the start of oscillation cycle,

- Time taken to reach from the first minima to the first maxima,

As we know that an oscilloscope executes a wave cycle represented by a sine wave. So we can deduce that it has executed one-fourth of the cycle in going from the amplitude of 20 units to 100 units in 0.005 seconds.
<u>So the time taken to complete one cycle of the oscillation:</u>

is the time period of the oscillation
<u>We know frequency:</u>



We have: K.E. = mv² / 2
here, m = 4 Kg
v = 9 m/s
Substitute their values into the expression:
K.E. = (4)(9)² / 2
K.E. = (4)(81) / 2
K.E. = 324 / 2
K.E. = 162 Joules
In short, Your Answer would be 162 J
Hope this helps!
Answer:
The magnitude of the net force F₁₂₀ on the lid when the air inside the cooker has been heated to 120 °C is 
Explanation:
Here we have
Initial temperature of air T₁ = 20 °C = 293.15 K
Final temperature of air T₁ = 120 °C = 393.15 K
Initial pressure P₁ = 1 atm = 101325 Pa
Final pressure P₂ = Required
Area = A
Therefore we have for the pressure cooker, the volume is constant that is does not change
By Chales law
P₁/T₁ = P₂/T₂
P₂ = T₂×P₁/T₁ = 393.15 K× (101325 Pa/293.15 K) = 135,889.22 Pa
∴ P₂ = 135.88922 KPa = 135.9 kPa
Where Force =
we have
Force =
.