A baseball of mass 250g, pitched with a speed of 40m/s is caught by the catcher, whose glove moves backward 0.25m while stopping the ball. What was the kinetic energy of the ball before it was caught?
Answers
Answer 1
Answer:
I don't think we care about the motion of the catcher's glove.
The mass of the ball is 0.25kg and its speed is 40m/s. So its kinetic energy is . . .
KE = 1/2 (mass) (speed)² =
(0.125 kg) (40m/s)² =
200 kg-m²/s² = 200 joules .
Answer 2
Answer:
The kinetic energy is =.5mv^2 so the amount the glove moved beforehand is irrelevant and typically this is measured in Kgm/s so 250g is .25kg and v^2 is 40x40 so 1600 lastly 1600x.5x.25 is 200kgm/s :)
Suppose that you are riding a bike away from your dog who sits and watches you leave. If you use the bicycle as a reference frame, how does your dog appear to move?
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If you use the bicycle as a reference frame, your dog will appear to be moving backwards farther from you/your bicycle. Although the dog is sitting on one place, your bicycle is moving away from the dog.
What is the difference in the charges on a ballon rubbed in your hair and a glass rod rubbed
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The balloon steals electrons from your hair, leaving the hair positively charged, and the balloon negatively charged. It causes hair to be apart from each other, because it has the same charge. Glass has a weaker hold on electrons, and silk absorbs the lost electrons.
What is the mass of a child if the force of gravity on the child's body is 100 N?
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Gravity is 9.81m/s^2 on earth F=m×g 100N=(x)kg×9.81m/s^2 x=10.19kg or more than 22lbs
How does the concentration of a hydrogen ion affect the ph levels of a substance?
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Acidic and basic are two extremes that describe chemicals, just like hot and cold are two extremes that describe temperature. Mixing acids and bases can cancel out their extreme effects, much like mixing hot and cold water can even out the water temperature. A substance that is neither acidic nor basic is neutral.
The character of acidic, basic and neutral is defined by the concentration of hydrogen ions [H+](mol/L). A solution with a concentration of hydrogen ions higher than 10-7mol/L is acidic, and a solution with a lower concentration is alkaline (another way to say basic). Using the formula, pH=-log[H+], a pH of 7 is neutral, a pH less than 7 is acidic, and a pH greater than 7 is basic. As one can see from this formula, ten times a given concentration of hydrogen ions means one unit lower in terms of pH value (higher acidity), and vice versa.
Pure water is neutral, with a pH of 7.0. When chemicals are mixed with water, the mixture can become either acidic or basic. Vinegar and lemon juice are acidic substances, while laundry detergents and ammonia are basic.
Chemicals that are very basic or very acidic are called "reactive." These chemicals can cause severe burns. Automobile battery acid is an acidic chemical that is reactive. Automobile batteries contain a stronger form of some of the same acid that is in acid rain. Household drain cleaners often contain lye, a very alkaline chemical that is reactive.
Juan measured the temperature of salt water. He then added 273 to the measured value. Which conversion is Juan most likely doing? degrees Celsius to degrees Fahrenheit degrees Celsius to kelvins kelvins to degrees Celsius degrees Fahrenheit to degrees Celsius
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Answer:
degrees Celsius to kelvins
Explanation:
True or False.. Although the Kinetic Theory of Matter states that the particles that make up all matter are in perpetual motion, we know that this isn’t really correct because solids don’t move.
Answers
The answer is false because kinetic energy contains motion!
The answer is false because the Kinetic Theory of Matter does not involve particles that make up all matter