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Tanzania [10]
3 years ago
7

You are in a speedboat on a river moving in the same direction as the current. The speedometer on the boat shows that its speed

is 20 km/h. However, a person on the shore measures the boat's speed as 23 km/h. How is this possible?
Physics
1 answer:
zloy xaker [14]3 years ago
5 0
From the reference point of the river, the speed of the boat is 20 km/h. From the reference point of someone standing on the shore, the speed of the boat is the speed on the speedometer plus the downstream speed of the current.
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The diagram shows four paths from point A to point B.
iVinArrow [24]
Path 2.

Displacement is the direction and magnitude of an object from its starting point, so path 2 is the direct route you would need to take to find direction and magnitude.
8 0
2 years ago
X rays of wavelength 0.0169 nm are directed in the positive direction of an x axis onto a target containing loosely bound electr
mamaluj [8]

Answer:

a) 4.04*10^-12m

b) 0.0209nm

c) 0.253MeV

Explanation:

The formula for Compton's scattering is given by:

\Delta \lambda=\lambda_f-\lambda_i=\frac{h}{m_oc}(1-cos\theta)

where h is the Planck's constant, m is the mass of the electron and c is the speed of light.

a) by replacing in the formula you obtain the Compton shift:

\Delta \lambda=\frac{6.62*10^{-34}Js}{(9.1*10^{-31}kg)(3*10^8m/s)}(1-cos132\°)=4.04*10^{-12}m

b) The change in photon energy is given by:

\Delta E=E_f-E_i=h\frac{c}{\lambda_f}-h\frac{c}{\lambda_i}=hc(\frac{1}{\lambda_f}-\frac{1}{\lambda_i})\\\\\lambda_f=4.04*10^{-12}m +\lambda_i=4.04*10^{-12}m+(0.0169*10^{-9}m)=2.09*10^{-11}m=0.0209nm

c) The electron Compton wavelength is 2.43 × 10-12 m. Hence you can use the Broglie's relation to compute the momentum of the electron and then the kinetic energy.

P=\frac{h}{\lambda_e}=\frac{6.62*10^{-34}Js}{2.43*10^{-12}m}=2.72*10^{-22}kgm\\

E_e=\frac{p^2}{2m_e}=\frac{(2.72*10^{-22}kgm)^2}{2(9.1*10^{-31}kg)}=4.06*10^{-14}J\\\\1J=6.242*10^{18}eV\\\\E_e=4.06*10^{-14}(6.242*10^{18}eV)=0.253MeV

5 0
3 years ago
A baseball is thrown with an initial velocity of 45.4 m/s at an angle of 31.2 ∘ .
sveticcg [70]

Answer:

V (initial vertical velocity) = 45.4 sin 31.2 = 23.52 m/s

1/2 m V^2 = m g h      conservation of energy

h = V^2 / (2 g) = 23.52^2 / 19.6 = 28.2 m       max height

Check:

t = 28.2 / 9.8 = 2.88 sec    time to reach max height

h = 23.52 * 2.88 - 1/2 g 2.88^2 = 27.1 m

8 0
2 years ago
All but one statement applies to electromagnetic radiation
lina2011 [118]
<span>D) Electromagnetic radiation travels in the form of longitudinal waves.</span>
3 0
3 years ago
Hoover Dam on the Colorado River is the highest dam in the United States at 221m, with a power output of 680 MW. The dam generat
DiKsa [7]

Answer:

The power in this flow is 9.56\times10^{8}\ W

Explanation:

Given that,

Distance = 221 m

Power output = 680 MW

Height =150 m

Average flow rate = 650 m³/s

Suppose we need to calculate the power in this flow in watt

We need to calculate the pressure

Using formula of pressure

Pressure=\rho g h

Where, \rho= density

h = height

g = acceleration due to gravity

Put the value into the formula

Pressure=1000\times9.8\times150

Pressure=1470000\ Nm^2

We need to calculate the power

Using formula of power

P=Pressure\times flow\ rate

Put the value into the formula

P=1470000\times650

P=9.56\times10^{8}\ W

Hence, The power in this flow is 9.56\times10^{8}\ W

5 0
3 years ago
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