Answer:
A)
B)
Explanation:
Given:
mass of car,
A)
frequency of spring oscillation,
We knkow the formula for spring oscillation frequency:
Now as we know that the springs are in parallel and their stiffness constant gets added up in parallel.
<u>So, the stiffness of each spring is (as they are identical):</u>
B)
given that 4 passengers of mass 70 kg each are in the car, then the oscillation frequency:
Answer:
P = 4.5 watts
Explanation:
Given that,
EMF of the circuit, E = 3 volt
The resistance of the resistors, R = 2 ohms
We need to find the power of this circuit. The relation between power, emf and resistance is given by the formula as follows :
Substitute all the values,
So, the power of this circuit is equal to 4.5 watts.
Answer:
K.E₂ = mg(h - 2R)
Explanation:
The diagram of the car at the top of the loop is given below. Considering the initial position of the car and the final position as the top of the loop. We apply law of conservation of energy:
K.E₁ + P.E₁ = K.E₂ + P.E₂
where,
K.E₁ = Initial Kinetic Energy = (1/2)mv² = (1/2)m(0 m/s)² = 0 (car initially at rest)
P.E₁ = Initial Potential Energy = mgh
K.E₂ = Final Kinetic Energy at the top of the loop = ?
P.E₂ = Final Potential Energy = mg(2R) (since, the height at top of loop is 2R)
Therefore,
0 + mgh = K.E₂ + mg(2R)
<u>K.E₂ = mg(h - 2R)</u>
Answers with Explanations:
1. Answer: True
Explanation:
Muscle cramps happen especially during an <em>"intense workout."</em> The frequency of cramps is related to heat, thus it is important to<u> stay hydrated</u> all throughout the workout. Eating should be done<em> at least 2 to 3 hours</em> <em>prior to workout</em> because eating immediately before exercise leads to undigested food. Such kind of food causes cramps.
2. Answer: True
Explanation: Applying direct pressure immediately after the injury can help <em>decrease bleeding.</em> Blood loss results to <u>blood that is collected under the skin. </u>This turns into the color of blue or black, also known as "bruise." Decrease bleeding would then mean decrease bruising.
Applying pressure also <em>decreases swelling </em>because it restricts the blood flow and fluid from reaching into the injury.
3. Answer: False
Explanation: "Lordosis" refers to the body's<em> natural lordotic curve</em>. This is considered "normal." The excessive inward curve of the lumbar spine is called "hyperlordosis." This is commonly caused by<u> poor posture, lack of exercise, obesity and spinal conditions.</u>
4. Answer: False
Explanation: The mnemonic acronym "RICE" stands for<em> Rest, Ice, Compression</em><em> (not Cold)</em> and<em> Elevation</em>. This term is commonly used in First Aid and was introduced by Gabe Mirkin in 1978.
5. Answer: True
Explanation: Keeping the proper posture during exercise <u><em>prevents the body from encountering injuries</em></u>. It also ensures that the body is executing the exercise by<u> using the muscles properly.</u>
6. Answer: False
Explanation: "Ice" is important in<em> decreasing the swelling of the injury</em>. It constricts the blood vessels which prevents the flow of blood and other fluids towards the site of injury.
7. Answer: False
Explanation: The spine is naturally straight if a person doesn't have a medical problem. However, scoliosis is a medical problem. It is <u>a condition wherein a person's spine is </u><u>curved</u>, rather than being straight.
8. Answer: True
Explanation: When it comes to exercise,<em> starting slow</em> is the main key. It is followed by<u> gradual building up.</u> The increase will depend on the person's stamina. For example, <em>starting with a warm-up, followed by a slow walk then pacing up to a brisk walk.</em>
9. Answer: True
Explanation: Kyphosis is a spinal condition wherein the person's spine is <em>excessively curved outward.</em> This causes the upper back and the shoulders to be rounded. This condition is commonly called "hunchback."
10. Answer: True
Explanation: Proper posture entails the right amount of spinal curve. This means that the spine is in "neutral position." This means that the spine takes on the "S-shape." A little amount of curve results to a<em> "flat back</em>" while too much curve results to a <em>"swayback</em>."
11. Answer: all of the above
Explanation: Body posture and technique are important especially when it comes to exercise. Poor posture and technique lead to strain on joints, ligaments and injury especially to the muscles. This also puts the body out of alignment.
12. Answer: True
Explanation: Stretching is appropriately done at the<u> end of a warm-up</u> when the temperature has increased because at this time, the muscles are already flexible. It allows the muscles to be loosened and also aids in better performance during workouts or exercises.
13. Answer: False
Explanation: "Lifting" with your back only will result to muscle injury. There are several ways to do lifting such as "pull-ups" or "lat pull downs." This means that you are not lifting with your back only but using your other joints and muscles for lifting.
14. Answer: True
Explanation: "Warming-up" is an essential preparation before any workout because it prepares the body by<em> increasing temperature</em> and <em>blood flow to the muscles</em>. Without it, the muscles will become sore and the chance for injuries increases.
15. Answer: True
Explanation: "Cool down" is considered equally important as "warm-up." <u>It lowers the body's temperature </u>and lowers the amount of lactic acid that causes<u> muscle cramping, soreness and stiffness.</u>
16. Answer: True
Explanation: It is said that<em> most people forget about warming up and cooling down before and after they work out</em>. It is necessary to have 5 to 10 minutes of warm-up and cool down for every exercise routine.
17. Answer: False
Explanation: Knee extension is <em>best done at 90 degrees angle</em> as advised by most health experts. However, it depends on your capability and your exercise goals. For some people, <u>extending beyond 90 degrees is beneficial.</u>
18. Answer: True
Explanation: Tucking your belly button helps with your body's core exercise. If this is going to be done throughout the day, then surely it will strengthen the muscles. This can be done while a person is sitting down or walking.
