Author: admin
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Vector Quantities
A vector quantity is a physical quantity that has both magnitude and direction. In other words, a vector quantity is described by a number, a unit, and a direction. Examples of vector quantities include velocity, acceleration, force, displacement, and momentum. These quantities are commonly represented graphically using arrows to show both their direction and magnitude.…
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Scalar Quantities Definition
A scalar quantity is a physical quantity that has only magnitude and no direction. In other words, a scalar quantity is described only by a number and a unit, and it does not have any associated direction or vector. Examples of scalar quantities include temperature, mass, time, distance, speed, and energy. These quantities can be…
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Scalar and Vector
Scalar and Vector Quantities are used to describe the motion of an object. Scalar Quantities are defined as physical quantities that have magnitude or size only. For example, distance, speed, mass, density, etc. However, vector quantities are those physical quantities that have both magnitude and direction like displacement, velocity, acceleration, force, etc. It should be noted that when a vector…
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Check Your Understanding
3. What is linear momentum? 4. If an object’s mass is constant, what is its momentum proportional to? 5. What is the equation for Newton’s second law of motion, in terms of mass, velocity, and time, when the mass of the system is constant? 6. Give an example of a system whose mass is not…
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Practice Problems
1 . A 5 kg bowling ball is rolled with a velocity of 10 m/s. What is its momentum? 2 . (credit: modification of work from Pinterest) A 155-g baseball is incoming at a velocity of 25 m/s. The batter hits the ball as shown in the image. The outgoing baseball has a velocity of 20 m/s…
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Venus Williams’ Racquet
During the 2007 French Open, Venus Williams (Figure 8.3) hit the fastest recorded serve in a premier women’s match, reaching a speed of 58 m/s (209 km/h). What was the average force exerted on the 0.057 kg tennis ball by Williams’ racquet? Assume that the ball’s speed just after impact was 58 m/s, the horizontal…
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A Football Player and a Football
(a) Calculate the momentum of a 110 kg football player running at 8 m/s. (b) Compare the player’s momentum with the momentum of a 0.410 kg football thrown hard at a speed of 25 m/s. STRATEGY No information is given about the direction of the football player or the football, so we can calculate only…
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Saving Lives Using the Concept of Impulse
Cars during the past several decades have gotten much safer. Seat belts play a major role in automobile safety by preventing people from flying into the windshield in the event of a crash. Other safety features, such as airbags, are less visible or obvious, but are also effective at making auto crashes less deadly (see Figure…
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Hand Movement and Impulse
In this activity you will experiment with different types of hand motions to gain an intuitive understanding of the relationship between force, time, and impulse. Procedure: What are some other examples of motions that impulse affects?
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Newton’s Second Law in Terms of Momentum
When Newton’s second law is expressed in terms of momentum, it can be used for solving problems where mass varies, since Δ𝐩=Δ(𝑚𝐯)Δp=Δ(�v) . In the more traditional form of the law that you are used to working with, mass is assumed to be constant. In fact, this traditional form is a special case of the law, where…