Answer:
Dogs are able to hear much higher frequencies than humans are capable of detecting. For this reason, dog whistles that are inaudible to the human ear can be heard easily by a dog. If a dog whistle has a frequency of 30,000 Hz, what is the wavelength of the sound emitted?
Answer:
49.3 N
Explanation:
Given that Pulling up on a rope, you lift a 4.25 kg bucket of water from a well with an acceleration of 1.80 m/s2 . What is the tension in the rope?
The weight of the bucket of water = mg.
Weight = 4.25 × 9.8
Weight = 41.65 N
The tension and the weight will be opposite in direction.
Total force = ma
T - mg = ma
Make tension T the subject of formula
T = ma + mg
T = m ( a + g )
Substitutes all the parameters into the formula
T = 4.25 ( 1.8 + 9.8 )
T = 4.25 ( 11.6 )
T = 49.3 N
Therefore, the tension in the rope is 49.3 N approximately.
Djdjdjddjddkjddiejrjrrjrjrkrkrkrjrjr
KE = (1/2)·(mass)·(speed)²
KE = (1/2)·(50 kg)·(18 m/s)²
KE = (25 kg)·(324 m²/s²)
KE = 8,100 kg-m²/s²
KE = 8,100 Joules
Can something have energy even if it's not moving?
All moving objects have kinetic energy. When an object is in motion, it changes its position by moving in a direction: up, down, forward, or backward. ... Potential energy is stored energy. Even when an object is sitting still, it has energy stored inside that can be turned into kinetic energy (motion).
Does a book at rest have energy?
A World Civilization book at rest on the top shelf of a locker possesses mechanical energy due to its vertical position above the ground (gravitational potential energy).
Does a book lying on a table have energy?
The book lying on a desk has potential energy; the book falling off a desk has kinetic energy.