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3 years ago

In the absence of a gravitational field, you could determine the mass of an object (of unknown composition) by:

Physics

1 answer:

lina2011 [118]3 years ago

3 0

Answer:

A) By applying a known force, and measuring it's acceleration.

Explanation:

This is actually something that astronauts do in space as a mathmatical exercise when calculating the mass of an object since F = m × a.

Once the force, and acceleration are applied, the only unknown is the mass which can be solved by dividing force over acceleration. This is because inertial mass is equal to gravitational mass.

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Two 65.0 kg ice skaters are standing 2.00 m away from each other in the ice. What is the gravitational attraction between the tw

Paladinen [302]

Answer:

A) 7×10⁻⁸ N

Explanation:

r = Distance between the two skaters = 2 m

m₁ = m₂ = Mass of the two skaters = 65 kg

G = Gravitational constant = 6.67 × 10⁻¹¹ m³/kgs²

From Newton's Law of Universal gravity

$F=G\frac{m_1m_2}{r^2}\\\Rightarrow F=6.67\times 10^{-11} \frac{65\times 65}{2^2}\\\Rightarrow F=7.045\times 10^{-8}\ N$

∴ Force of gravity between the two skaters is 7×10⁻⁸ N

7 0

4 years ago

A cube with sides of area 18 cm^2 contains a 6.0 nanoCoulomb charge. Find the flux of the electric field through the surface of

Vanyuwa [196]

Answer:

The flux of the electric field is 677.6 Nm²/C

Explanation:

Given that,

Area = 18 cm²

Charge = 6.0 nC

We need to calculate the flux of the electric field

Using Gauss's law

$\phi=\dfrac{q}{\epsilon_{0}}$

Where, q = charge

$\epsilon_{0}$ =permittivity of free space

Put the value into the formula

$\phi=\dfrac{6.0\times10^{-9}}{8.854\times10^{-12}}$

$\phi=677.6\ Nm^2/C$

Hence, The flux of the electric field is 677.6 Nm²/C.

4 0

3 years ago

In what way is Speed related to Kinetic Energy?

Papessa [141]

Answer:

Explanation:

In order to find kinetic energy, you need information about the velocity. Speed is the magnitude of the velocity.

Kinetic energy is 1/2mv^2

m being mass

v being velocity

8 0

3 years ago

A 64.1 kg runner has a speed of 3.10 m/s at one instant during a long-distance event.(a) What is the runner's kinetic energy at

Liono4ka [1.6K]

Answer:

(a) the runner's kinetic energy at the given instant is 308 J

(b) the kinetic energy increased by a factor of 4.

Explanation:

Given;

mass of the runner, m = 64.1 kg

speed of the runner, u = 3.10 m/s

(a) the kinetic energy of the runner at this instant is calculated as;

$K.E_i = \frac{1}{2} mu^2\\\\K.E_i = \frac{1}{2} \times 64.1 \times 3.1^2\\\\K.E_i = 308 \ J$

(b) when the runner doubles his speed, his final kinetic energy is calculated as;

$K.E_f = \frac{1}{2} mu_f^2\\\\K.E_f = \frac{1}{2} m(2u)^2\\\\K.E_f = \frac{1}{2} \times 64.1 \ \times (2\times 3.1)^2\\\\K.E_f = 1232 \ J$

the change in the kinetic energy is calculated as;

$\frac{K.E_f}{K.E_i} = \frac{1232}{308} =4$

Thus, the kinetic energy increased by a factor of 4.

4 0

3 years ago

Point A and B located at 4 meters and 9 meters from a source of the sound. If IA and IB are intensity at point A and point B, th

elena-14-01-66 [18.8K]

The intensity ratio at point A and B will be 81:16.

<u>Explanation:</u>

Sound waves are known to get faded with increase in the distance. This is because, the intensity of the sound is inversely proportional to the square of the distance of the source from the observer. So, if an observer is standing greater distance from the source of the sound, he/she will find difficulty in hearing the sound.

So, as the distance between the source and observer increases, the intensity of the sound wave decreases.

$I = \frac{1}{r^{2} }$

As here two points A and B are located at 4 m and 9 m distance from the source, then the intensity of sound at A and B will be inversely proportional to their respective square of the distance as shown below.

$I_{A} =\frac{1}{r_{A}^{2} } = \frac{1}{4 \times 4}=\frac{1}{16}$

Similarly,

$I_{B} =\frac{1}{r_{B}^{2} } = \frac{1}{9 \times 9}=\frac{1}{81}$

So, the ratio of intensity at point A and B will be

$\frac{I_{A} }{I_{B} } = \frac{81}{16} =81:16$

Thus, the intensity ratio at point A and B will be 81:16.

7 0

3 years ago