b. how long does it take dave to cross the river?

c. how far downstream is dave’s landing point?

d. how long would it take dave to cross the river if there were no current?

Answer:

a) Let's call x the direction parallel to the river and y the direction perpendicular to the river.

Dave's velocity of 4.0 m/s corresponds to the velocity along y (across the river), while 6.0 m/s corresponds to the velocity of the boat along x. Therefore, the drection of Dave's boat is given by:

relative to the direction of the river.

b) The distance Dave has to travel it S=360 m, along the y direction. Since the velocity along y is constant (4.0 m/s), this is a uniform motion, so the time taken to cross the river is given by

c) The boat takes 90 s in total to cross the river. The displacement along the y-direction, during this time, is 360 m. The displacement along the x-direction is

so, Dave's landing point is 540 m downstream.

d) If there were no current, Dave would still take 90 seconds to cross the river, because its velocity on the y-axis (4.0 m/s) does not change, so the problem would be solved exactly as done at point b).

When UV light of wavelength 248 nm is shone on aluminum metal, electrons are ejected withmaximum kinetic energy 0.92 eV. What maximum wavelength of light could be used to ejectelectrons from aluminum

A firefighting crew uses a water cannon that shoots water at 27.0 m/s at a fixed angle of 50.0 ∘ above the horizontal. The firefighters want to direct the water at a blaze that is 12.0 m above ground level. How far from the building should they position their cannon? There are two possibilities (d1Part A:d1=_____mPart B:d2=______m

An alternating current is supplied to an electronic component with a rating that the voltage across it can never, even for an instant, exceed 16 V. What is the highest rms voltage that can be supplied to this component while staying below the voltage limit?A)8 sqrt 2 VB) 16 sqrt 2 VC) 256 VD) 8

According to the second law of thermodynamics, it is impossible for ____________. According to the second law of thermodynamics, it is impossible for ____________. heat energy to flow from a colder body to a hotter body an ideal heat engine to have the efficiency of 99% an ideal heat engine to have non-zero power. a physical process to yield more energy than what is put in

If you travel 2 km north, then travel 5 km south, what is your displacement?

A firefighting crew uses a water cannon that shoots water at 27.0 m/s at a fixed angle of 50.0 ∘ above the horizontal. The firefighters want to direct the water at a blaze that is 12.0 m above ground level. How far from the building should they position their cannon? There are two possibilities (d1Part A:d1=_____mPart B:d2=______m

An alternating current is supplied to an electronic component with a rating that the voltage across it can never, even for an instant, exceed 16 V. What is the highest rms voltage that can be supplied to this component while staying below the voltage limit?A)8 sqrt 2 VB) 16 sqrt 2 VC) 256 VD) 8

According to the second law of thermodynamics, it is impossible for ____________. According to the second law of thermodynamics, it is impossible for ____________. heat energy to flow from a colder body to a hotter body an ideal heat engine to have the efficiency of 99% an ideal heat engine to have non-zero power. a physical process to yield more energy than what is put in

If you travel 2 km north, then travel 5 km south, what is your displacement?

**Answer:**

When you jump off a train, you jump off a certain height and your downwards (vertical) velocity is zero. But your forward (horizontal) velocity is not. You will hit the ground on split second with your horizontal velocity practically the same as the train.

**Explanation:**

you be in serious injury.

**Answer:**

**Explanation:**

The maximum expected measurement error for a pressure gauge measuring 0-10 bar with an inaccuracy of 1% of full-scale reading is 0.1 bar. When the gauge measures 1 bar, the expected inaccuracy is 10%.

The inaccuracy mentioned here is related to the full-scale reading which means the error is calculated based on the **top measurement value**. The pressure gauge range is 0-10 bar, so the inaccuracy is one percent of this. (a) Thus, the **maximum measurement error** expected for this instrument is 1.0% of 10 bar i.e., 0.1 bar. (b) If the gauge is measuring a pressure of **1 bar**, then the relative error expressed as a percentage would be the absolute error (0.1 bar) divided by the observed reading (1 bar) i.e., 10%. It means, when measuring 1 bar pressure, the expected measurement error is 10%. **This is an example of how instrument inaccuracy is properly interpreted and employed when working with various measurements**.

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**Explanation:**

a scientific theory is a well substantiated explanation of some aspect of the nature world, based on a body of facts that have been repeatedly confirmed through observation and experiment. search fact-supported theories are not "guesses" but reliable account of the real world .

The **baseball** curves better at a **flat****plain** due to contacting with **air**.

A **curveball** is a breaking pitch with more **movement** than most other pitches. It is thrown **slower** and with more overall **break** than a slider and is used to throw **hitters** off balance.

On a flat plain, a **baseball** will curve down better. This is due to the **curving** being caused by the ball contacting air and being **pushed** in a **specific****direction**.

The spin, **speed**, and **location** of the ball's **stitches** in relation to the air will all influence how it changes **direction** when pushed against.

Consider throwing a baseball in a **vacuum** where there is no air. Because there is no air to **push** on the ball, it will not **curve** at all.

Thus, a flat plain area will be better for **baseball** curve.

For more details regarding **curveball**, visit:

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A baseball will curve better down on a flat plain.In view of the fact that the curving is caused by the ball contacting the air and pushing the ball in a particular direction.

**Answer:**

**True**

**Explanation:**

- Faraday's Law says that there is a emf induced in a conductor when the vector flux of the magnetic field across it changes in time.
- This can be true due to one of two facts, either the magnitude of the magnetic field changes in time, or the area through which the flux occurs changes due to the movement of the object.
- In this case, due to the magnetic field is constant, and the coil stays at rest, there is no possible change in flux, so emf induced is zero.

**Answer:**

**Explanation:**

solution below

The **quantum of energy** for one atomic oscillator in tungsten, given the effective interatomic spring stiffness of 360 N/m, the mass of one tungsten atom as 3.074 x 10^-25 kg, and the reduced Planck's constant of 1.0546 x 10^-34 J · s, can be calculated to be approximately 1.33 x 10^-21 J.

To calculate the **quantum of energy** for one atomic oscillator in tungsten, we will consider the model of an atom being connected to two springs, both having an ** effective interatomic*** spring stiffness* of four times the given value (90 N/m). This value thus becomes 360 N/m.

One mole of tungsten has a mass of 0.185 kg, thus the mass of one atom can be determined by dividing this value by Avogadro's number (6.0221 x 10^23 molecules/mole), which gives approximately 3.074 x 10^-25 kg.

The quantum of energy, or the energy of one quantum (the smallest possible energy increment), is given by the formula E = ħω, where ħ is the reduced Planck's constant (1.0546 x 10^-34 J · s) and ω is the angular frequency, given by sqrt(k/m), where k is the spring constant and m is the mass.

Substituting the known values into these equations gives ω= sqrt((360)/(3.074 x 10^-25)) and E= (1.0546 x 10^-34) x sqrt((360)/(3.074 x 10^-25)), which results in a quantum of energy of approximately 1.33 x 10^-21 J.

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