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3 years ago

Which of the following is not an example of a physical change?

Physics

1 answer:

Mazyrski [523]3 years ago

8 0

Answer:

Explanation:

Cutting a string in half because

b is irreversible

c is a cheical and d is also a chemical change

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An airplane propeller is rotating at 1900 rpm (rev/min).

alexandr1967 [171]

Answer:

See explanation

Explanation:

We have to convert to angular velocity in rads-1 as follows;

Angular velocity in rad/s = 2π/60 × 1900 rpm = 199 rad/s

Given that

angular velocity =angle turned /time taken

Time taken = angle turned/angular velocity

Converting 35° to radians we have;

35 × π/180 = 0.61 radians

Time taken = 0.61 radians/199 rad/s

Time taken = 0.0031 seconds

3 0

3 years ago

Complete this sentence. Average speed is worked out from dividing _________ by ________

Dmitry [639]

Average speed is worked out from dividing distance by time.

3 0

3 years ago

Read 2 more answers

A scientist discovered an elementary particle paired with another particle. It has a positive charge equal to two–thirds of the

julia-pushkina [17]

W boson has +1e or - 1e charge, Z boson has 0 charge.

Leptons have +1e, -1e or 0 charge.

Photons have 0 charge.

Only quarks have a charge of +2/3e or -1/3e of an electron charge.

To be exact, only up-type quarks (Up, Down and Top quarks) have a +2/3e or two thirds of an electron charge.

So the correct answer is D) Quark.

6 0

3 years ago

Saturn has an orbital period of 29.46 years. In two or more complete sentences, explain how to calculate the average distance fr

soldi70 [24.7K]

$Given:\\T=29.46y\approx 9.29\cdot 10^8s\\M_S\approx2.0\cdot 10^{30}kg\\G=6.67\cdot 10^{-11} \frac{m^3}{kg\cdot s^2} \\\\Find:\\R=?\\\\Solution:\\\\F_g= G\frac{mM_s}{R^2} \\\\F_c= \frac{mv^2}{R} \\\\F_g=F_c\\\\G\frac{mM_s}{R^2}=\frac{mv^2}{R} \Rightarrow G\frac{M_s}{R^2}=\frac{v^2}{R}\\\\v=\omega r\\\\G\frac{M_s}{R^2}= \frac{\omega^2R^2}{R}\Rightarrow G\frac{M_s}{R^2}=\omega^2R \\\\\omega= \frac{2 \pi }{T} \\\\G\frac{M_s}{R^3}= \frac{4 \pi ^2}{T^2}$

$GM_ST^2=4 \pi ^2R^3\Rightarrow R= \sqrt[3]{ \frac{GM_ST^2}{4 \pi ^2} }\\\\\\R= \sqrt[3]{ \frac{6.67\cdot 10^{-11} \frac{m^3}{kg\cdot s^2}\cdot2.0\cdot 10^{30}kg( 9.29\cdot 10^8s)^2}{4\cdot 3.14^2} } \approx 1.42\cdot 10^{12}m$

3 0

3 years ago

A particle moves along the x axis according to the equation x = 6t², where x is in meters and t is in seconds. Therefore:

vladimir2022 [97]

Answer is E

time can be negative.
A is not true because a=d2xdt2=12 m/s2
C: question already said that particle move along x-axis, which is not parabola path.
D: velocity is dxdt=12t, therefore velocity changes by 12 m/s and not 9.8 m/s
So we are left with E.

7 0

3 years ago