Mechanical energy (ME) is the sum of potential energy (PE) and kinetic energy (KE). When the toy falls, energy is converted from PE to KE, but by conservation of energy, ME (and therefore PE+KE) will remain the same.
Therefore, ME at 0.500 m is the same as ME at 0.830 m (the starting point). It's easier to calculate ME at the starting point because its just PE we need to worry about (but if we wanted to we could calculate the instantaneous PE and KE at 0.500 m too and add them to get the same answer).
At the start:
ME = PE = mgh
ME = 0.900 (9.8) (0.830)
ME = 7.32 J
Hello,
It's D! hope I helped.
Answer:
Fundamental frequency in the string will be 25 Hz
Explanation:
We have given length of the string L = 1.2 m
Speed of the wave on the string v = 60 m/sec
We have to find the fundamental frequency
Fundamental frequency in the string is equal to 
, here v is velocity on the string and L is the length of the string
So frequency will be equal to 
So fundamental frequency will be 25 Hz
Answer:
With the exception of natural gas fossil fuel energies have seen an overall decrease since year 2000.
Explanation:
Just observe the graph
The Fossil fuels include-Petroleum ,coal and natural gases.
- The graph of these goes fastly up during 20th century but ,then it stabled at the peak then has not shown any solid increase .
- Observe other energy sources graph ,nuclear energy etc have shown quite speedy increase .
Option C is correct
Weight of the child m = 50 kg
Radius of the merry -go-around r = 1.50 m
Angular speed w = 3.00 rad/s
(a)Child's centripetal acceleration will be a = w^2 x r = 3^2 x 1.50 => a = 9 x
1.5
Centripetal Acceleration a = 13.5m/sec^2
(b)The minimum force between her feet and the floor in circular path
Circular Path length C = 2 x 3.14 x 1.50 => c = 3 x 3.14 => C = 9.424
Time taken t = 2 x 3.14 / w => t = 6.28 / 3 => t = 2.09
Calculating velocity v = distance / time = 9.424 / 2.09 m/s => v = 4.5 m/s
Calculating force, from equation F x r = mv^2 => F = mv^2 / r => 50 x (4.5)^2
/ 1.5
F = 50 x 3 x 4.5 => F = 150 x 4.5 => F = 675 N
(c)Minimum coefficient of static friction u
F = u x m x g => u = F / m x g => u = 675/ 50 x 9.81 => 1.376
u = 1.376
Hence with the force and the friction coefficient she is likely to stay on merry-go-around.
