A kitten pushes a ball of yarn rolling toward it at 1.00 cm/s with its nose, displacing the ball of yarn 17.5 cm in the opposite direction in 2.00 s. What is the acceleration of the ball of yarn?
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Answer 1
Answer:
The problem is very unclear. The way I understand it is like this: The yarn is rolling toward the cat, and from the instant the cat first touches the yarn, it moves 17.5 cm 2 sec, in the direction opposite to the way it was rolling.
Average speed during the 2 seconds after the bump = 17.5 / 2 = 8.75 cm/s .
Average speed = (1/2) (final speed away from the cat - 1 cm/sec towards the cat)
8.75 cm/s = (1/2) (final speed + 1) Multiply each side by 2 : 17.5 = final speed + 1 Final speed = 16.5 cm/s
Acceleration = (change in speed) / (time for the change)
Acceleration = (16.5 + 1) / (20) = 0.875 cm/s² .
My confidence level in this one is not excessive, but I'll submit it anyway, and somebody else can explain to me where I went wrong.
Why does the energy of a sound wave decrease over time
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Sound is a longitudinal wave that carries energy. Sound needs a medium to propagate through (this means that sound cannot propagate in vacuum).
The medium usually determines the speed of the wave travelling through it.
As the sound waves travel in a medium, this medium begins to decrease, therefore, the energy of the sound also decreases.
3. How many valence electrons are in the outermost energy level of each of the following elements? a. Helium b. Lithium c. Nitrogen d. Magnesium
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A.helium has no valency B.lithium has 1 C.nitrogen has either 5 or 3 because it bonds outer orbital D.magnesium has 2
A water balloon was dropped from a high window and struck its target 1.1 seconds later. If the balloon left the person's hand at -5.0 m/sec, what was its velocity on impact?
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The acceleration of gravity on Earth is 9.8 meters per second every second. So in 1.1 second of falling, an object gains (9.8 x 1.1) = 10.78 meters per second of downward speed.
The balloon was already falling at 5 m/sec when the time began, and it gained another 10.78 m/sec on the way. So at the end of 1.1 second, its downward speed was (5.0 + 10.78) = 15.78 m/sec.
Its velocity was 15.78 m/sec downward.
What is the formula for volume using density and mass
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The definition of density is
Density = (mass) / (volume)
Multiply each side by 'volume' : (density) x (volume) = (mass)
Divide each side by 'density' : Volume = (mass) / (density)
V=M/D volume=mass/density
Compare and contrast the general characteristics of a gas giant planet and one of the inner planets (such as Mercury, Earth, Venus or Mars)? Give two differences and one similarity.
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The gas planets usually have extremely high gravitational pulls, the surface isn't solid (since its a gas planet), and gas planets are larger than the inner planets. Similarities- These planets all have moons and they both revolve around the sun (obviously).
Hope this helps.
A bulldozer does 45,000 joules of work to push a boulder a distance of 30 meters.How much force is applied to push the?