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4 years ago

A race car makes one lap around a track of radius 50 m in 9.0 s. What is the average velocity? *

1 answer:

8 0

With velocity, you have to be careful. With velocity, it doesn't matter how much total distance you covered while you were moving. All that matters is the straight-line distance between the place you started from and the place where you stopped.

If you ended in the same place where you started from, then it doesn't matter whether you drove around town all day and then came home, or ran around laps on a circular track, or zig-zagged back and forth a hundred times. The straight distance from your start-point to your end-point is zero. So technically, according to the defintion of velocity, it was <em>ZERO</em>.

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1 poir

djverab [1.8K]

Answer:

D) 735 J(oules)

Explanation:

Work is defined as force * distance

Force is defined as mass * acceleration

Given a mass of 15 kg and a gravitational acceleration of 9.8 m/s² since the box is being lifted up, the force being applied to the box is 15 kg * 9.8 m/s² = 147 N

Since the distance is 5 meters, the work done is 147 N * 5 m = 735 N/m = 735 J, making D the correct answer.

4 0

3 years ago

If a spaceship has a momentum of 30,000 kg-m/s to the right and a mass of

m_a_m_a [10]

Answer:

75m/s

Explanation:

...................

8 0

3 years ago

A binary star system consists of two equal mass stars that revolve in circular orbits about their center of mass. The period of

Vladimir79 [104]

Answer:

$m = 2.23 \times 10^{-32} kg$

Explanation:

Given data:

PERIOD OF MOTION IS T = 25.5 days

orbital speeds = 220 km/s

we know that

acceleration due to centripetal force is $a = \frac{F}{m} = \frac{V^2}{r}$

Gravitational force $F= \frac{Gm m}{d^2}$

we know that

$v = \frac{2\pi R}{T}$

solving for

$R = \frac{vT}{2\pi}$

$F = \frac{Gm^2}{4(\frac{vT}{2\pi})^2}$

$F = G\times \frac{\pi m}{(vT)^2}$

$a = \frac{v^2}{\frac{vT}{2\pi}}$

$a = \frac{2\pi v}{T}$

we know that

f =ma

$G\times \frac{\pi m}{(vT)^2} = a = \frac{2\pi m v}{T}$

solving for m

$m = \frac{2Tv^3}{\pi G}$

$m = \frac{2\times 25.5 \times 86400 \times 220000^3\ m/s}{\pi \times 6.67\times 10^{-11}}$

$m = 2.23 \times 10^{-32} kg$

5 0

3 years ago

Describes the relationship between the spectrum of one atom and the spectrum of another?

krok68 [10]

The relationship between the number of visible spectral lines are identical for atoms .However they have unique wavelengths.

Option B

<u> Explanation:</u>

A spectrum is a range of frequencies or a range of wavelengths. The photon energy of the emitted photon is equal to the difference between two states. For every atom there are quite many electron transitions and each has a energy difference.

This difference in wavelength causes spectrum .As each element emission spectrum is unique because each atom has different energy and causes uniqueness in the emission spectrum . Hence, due to the difference in energy it emits different wavelengths.

6 0

3 years ago

An electron follows a helical path in a uniform magnetic field of magnitude 0.340 T. The pitch of the path is 6.00 µm, and the m

dedylja [7]

Answer:

The electron's speed is 34007.35 m/s

Explanation:

It is given that,

Magnetic field, B = 0.34 T

Magnetic force on the electron, $F=1.85\times 10^{-15}\ N$