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3 years ago

A cyclist travels 21 km in 90 minutes. Calculate, in m s–1 , the speed of the cyclist.

Physics

1 answer:

sasho [114]3 years ago

7 0

Answer:

35/9 m/s

Explanation:

21 km = 21000 m

90 min = 90*60 s = 5400 s

21000/5400 = 35/9 m/s

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Calculate the initial (from rest) acceleration of a proton in a 5.00 x 10^6 N/C electric field (such as created by a research Va

julsineya [31]

Answer:

Acceleration of the proton will be equal to $4.79\times 10^{14}m/sec^2$

Explanation:

We have given electric field $E=5\times 10^6N/C$

Mass of proton is equal to $m=1.67\times 10^{-27}kg$

And charge on proton is equal to $e=1.6\times 10^{-19}C$

Electrostatic force will be responsible for the motion of proton

Electrostatic force will be equal to $F=qE=1.6\times 10^{-19}\times 5\times 10^6=8\times 10^{-13}N$

According to newton law force on the proton will be equal to F = ma, here m is mass of proton and a is acceleration

This newton force will be equal to electrostatic force

So $1.67\times 10^{-27}\times a=8\times 10^{-13}$

$a=4.79\times 10^{14}m/sec^2$

So acceleration of the proton will be equal to $4.79\times 10^{14}m/sec^2$

5 0

3 years ago

A rotating wheel requires 5 s to rotate 38 revolutions. Its angular velocity at end of time interval 5-s is 79 rad/s. What is th

Lera25 [3.4K]

"Rotating wheel" is meant to indcate that the wheel is already rotating at the start. Denote the initial angular velocity by ω₀. Then the angular displacement θ at time t is

θ = ω₀t + 1/2 αt ²

while the angular velocity ω is

ω = ω₀ + αt

It takes 5 s for the wheel to rotate 38 times, or turn a total of (2π rad/rev) (38 rev) = 76π rad, as well as to reach an angular velocity of 79 rad/s, so that

76π rad = ω₀ (5 s) + 1/2 α (5 s)²

79 rad/s = ω₀ + α (5 s)

Solve the second equation for ω₀ and substitute into the first equation, then solve for α :

ω₀ = 79 rad/s - α (5 s)

==> 76π rad = (79 rad/s - α (5 s)) (5 s) + 1/2 α (5 s)²

==> 76π rad = (79 rad/s) (5 s) - 1/2 α (5 s)²

==> 1/2 α (5 s)² = (79 rad/s) (5 s) - 76π rad

==> α = ((79 rad/s) (5 s) - 76π rad) / (1/2 (5 s)²)

==> α ≈ 12.5 rad/s²

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3 years ago

State two (2) examples of osmosis occurring in everyday life

VMariaS [17]

When you keep raisin in water and the raisin gets puffed.
Movement of salt-water in animal cell across our cell membrane.

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3 years ago

Where would you most likely find regional metamorphism? associated with a mountain belt associated with a volcano associated wit

vladimir1956 [14]

Regional metamorphism is a type of metamorphism in which the minerals and the textures of the rocks are changed or altered due to the effect of pressure and heat over a wide area or region.
This type of metamorphism often results in metamorphic rocks that are strongly foliated.
Metamorphism usually occurs in the folds of thrust mountain belts.

Answer: You would most likely find regional metamorphism associated with a mountain belt.

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3 years ago

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It took David 2 seconds to lift a 5 Newton bag of toys from the floor to the top of the top shelf, which is 3 meters tall. How m

just olya [345]

So power is equal to work over time and work is force times distance, you do 5 times 3 and get 15 dividing by 2 gives us 7.5 W answer c

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3 years ago