Answer:
222.2N/m
Explanation:
Given parameters:
Elastic potential energy = 4000J
Extension = 6m
Unknown:
Spring coefficient = ?
Solution:
The elastic potential energy is the energy stored within a string.
It is expressed as;
EPE = k e²
k is the spring constant
e is the extension
4000 = x k x 6²
8000 = 36k
k = 222.2N/m
Answer:
Work done, W = 1.44 kJ
Explanation:
Given that,
Mass of boy, m = 74 kg
Initial speed of boy, u = 1.6 m/s
The boy then drops through a height of 1.56 m
Final speed of boy, v = 8.5 m/s
To find,
Non-conservative work was done on the boy.
Solution,
The work done by the non conservative forces is equal to the sum of total change in kinetic energy and total change in potential energy.
W = 1447.21 Joules
or
W = 1.44 kJ
Therefore, the non conservative work done on the boy is 1.44 kJ.
Oscillation is a type of periodic motion which repeats itself to and from about a point which is called mean position. The period of a Pendulum can be described as a ratio between the length and gravity as,
Here,
L = length
g = Gravity
If we rearrange to find the length we have that,
Our period is 2s and the gravity is 9.8m/s^2, then,
The simple required length of the pendulum must be 0.9929m