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AleksandrR [38]

3 years ago

13

A 58 kg boy and a 38 kg girl use an elastic rope while engaged in a tug-of-war on a frictionless icy surface. If the acceleratio

n of the girl toward the boy is 2.4 m/s 2 , determine the magnitude of the acceleration of the boy toward the girl. Answer in units of m/s 2 .

1 answer:

Arada [10]3 years ago

6 0

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A mars prototype carrying scientific instruments has a mass of 1060kg. a net force of 52000 n is applied to this roverat a test

Nitella [24]

F = 52000 N

m = 1060 kg

a= F/m = 52000 N/1060 kg = 49.0566 m/s^2

8 0

4 years ago

A uniform solid disk rolls without slipping down an incline making an angle θ with the horizontal. What is its acceleration? (En

Maru [420]

Answer:

aCM = (2/3)*g*Sin θ

Explanation:

Consider a uniform solid disk having mass M, radius R and rotational inertia I about its center of mass, rolling without slipping down an inclined plane.

In order to get the linear acceleration of the object’s center of mass, aCM ,

down the incline, we analyze this as follows:

The force of gravity (W = Mg) acting straight down is resolved into components parallel and perpendicular to the incline.

Since the object rolls without slipping there is a force of friction (Ff) acting on the object, at it’s point of contact with the incline, in the direction up the incline.

Newton’s 2nd Law gives then for acceleration down the incline

∑Fx' = m*aCM ⇒ m*g*Sin θ - Ff = m*aCM

The force of friction also causes a torque around the center of mass

having lever arm R so we can also write

τ = R*Ff = I*α

Solving for the friction, Ff = I*α / R

This is used in the expression derived from the 2nd Law:

m*g*Sin θ - Ff = m*g*Sin θ - (I*α / R) = m*aCM

The objects angular acceleration is related to the linear acceleration of the edge that contacts the incline by

a = R*α

Since the object rolls without slipping this has the same magnitude as aCM so we have that

α = aCM / R

Using this in

m*g*Sin θ - (I*α / R) = m*g*Sin θ - (I*(aCM / R) / R) = m*aCM

⇒ aCM = (m*g*Sin θ*R²) / (I + m*R²)

if I = (1/2)*m*R² (for a uniform solid disk)

we get

aCM = (2/3)*g*Sin θ

6 0

3 years ago

A hot (70°C) lump of metal has a mass of 250 g and a specific heat of 0.25 cal/g⋅°C. John drops the metal into a 500-g calorimet

Gnom [1K]

Answer:

d. 37 °C

Explanation:

$m_{m}$ = mass of lump of metal = 250 g

$c_{m}$ = specific heat of lump of metal = 0.25 cal/g°C

$T_{mi}$ = Initial temperature of lump of metal = 70 °C

$m_{w}$ = mass of water = 75 g

$c_{w}$ = specific heat of water = 1 cal/g°C

$T_{wi}$ = Initial temperature of water = 20 °C

$m_{c}$ = mass of calorimeter = 500 g

$c_{c}$ = specific heat of calorimeter = 0.10 cal/g°C

$T_{ci}$ = Initial temperature of calorimeter = 20 °C

$T_{f}$ = Final equilibrium temperature

Using conservation of heat

Heat lost by lump of metal = heat gained by water + heat gained by calorimeter

$m_{m} c_{m} (T_{mi} - T_{f}) = m_{w} c_{w} (T_{f} - T_{wi}) + m_{c} c_{c} (T_{f} - T_{ci}) \\(250) (0.25) (70 - T_{f} ) = (75) (1) (T_{f} - 20) + (500) (0.10) (T_{f} - 20)\\T_{f} = 37 C$

6 0

4 years ago

What is the relationship between air pressure and air temperature?

LenKa [72]

The relationship between the two is that air temperature changes the air pressure. For example, as the air warms up the molecules in the air become more active and they use up more individual space even though there is the same<span> number of molecules. This causes an </span>increase<span> in the air pressure.</span>

8 0

4 years ago

. Inside a laser apparatus, the stimulation and relaxation of electrons in atoms causes many photons with the same to be continu

mrs_skeptik [129]

Inside a laser apparatus, the stimulation and relaxation of electrons in atoms cause many photons with the same <u>wavelength </u>to be continuously emitted.

From the questions given, the main objective is to fill in the gaps and add important information where necessary. The missing information is highlighted in bold and underlined.

Inside a laser apparatus, the stimulation and relaxation of electrons in atoms cause many photons with the same <u>wavelength </u>to be continuously emitted.

2. When these photons are emitted, they travel between two <u>reflective </u>

surfaces to form the wave that is represented in the simulation.

3. This wave is the summation of all the photons being introduced with

every oscillation, and as they continue to travel, the amplitude

<u>increases. </u>

4. This occurs because the photons are emitted in a coherent fashion;

however, amplitude when the photons overlap in an incoherent

fashion.

5. In a laser device, a small portion of photons are permitted to escape

(for use in an application). This is emulated in the simulation, by

settling the Damping to Lots such that amplitude <u>remains relatively </u>

<u>constant </u>when compared to damping of None. (Damping

represents the Loss of photons.

6. The generation of multiple wavelengths is possible in some laser

producing systems, and the diffraction angle can be <u>varied</u> to allow

the isolation of different wavelengths.

7. Finally, when the power of a laser is described, the wave property

that is being referenced is a function of its frequency and

<u>amplitude.</u>

Therefore, we can conclude that we've fully understood the concept of emission of photons and wavelength in a laser apparatus.

Learn more about wavelength here:

brainly.com/question/23023103?referrer=searchResults

5 0

3 years ago