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2 years ago

When we draw a diagram of the forces acting on an extended object, the tail of the force vector for the weight should be at?

1 answer:

6 0

Whenever we represent forces using vectors, we ensure that the vector begins at the point of force exertion. In the case of weight, the point of exertion of the force is known as the center of gravity, which is the point through which the weight of an object can be said to act. Therefore, the downward arrow representing the weight would begin at the center of gravity of the object.

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In a bedridden patient recovering from a badly fractured femur, disuse atrophy in the thigh muscles is caused by _________.

Law Incorporation [45]

In a bedridden patient recovering from a badly fractured femur, disuse atrophy in the thigh muscles is caused by decreased synthesis of muscle proteins and/or increased breakdown of muscle proteins. Muscle tissue grows and heals in response to stress. Without the stress of exercise and normal daily activities, muscle tissue degenerates

3 0

2 years ago

A rock of mass m is thrown horizontally off a building from a height h. the speed of the rock as it leaves the thrower's hand at

Stells [14]

The correct answer is 3) $K_f = \frac{1}{2}mv_0^2 + mgh$ .

In fact, the total energy of the rock when it leaves the thrower's hand is the sum of the gravitational potential energy U and of the initial kinetic energy K:
 $E=U_i+K_i=mgh + \frac{1}{2}mv_0^2$
As the rock falls down, its height h from the ground decreases, eventually reaching zero just before hitting the ground. This means that U, the potential energy just before hitting the ground, is zero, and the total final energy is just kinetic energy:
 $E=K_f$ 
But for the law of conservation of energy, the total final energy must be equal to the tinitial energy, so E is always the same. Therefore, the final kinetic energy must be
 $K_f = mgh + \frac{1}{2}mv_0^2$

7 0

2 years ago

A charge of uniform volume density (40 nC/m3) fills a cube with 8.0-cm edges. What is the total electric flux through the surfac

GREYUIT [131]

Answer:

The flux through the surface of the cube is $2.314\ Nm^{2}/C$

Solution:

As per the question:

Edge of the cube, a = 8.0 cm = $8.0\times 10^{- 2}\ m$

Volume Charge density, $\rho_{v} = 40 nC/m^{3} = 40\times {- 9}\ C/m^{3}$

Now,

To calculate the electric flux:

$\phi = \frac{q}{\epsilon_{o}}$ (1)

where

$\phi$ = electric flux

$\epsilon_{o} = 8.85\times 10^{- 12}\ F/m$ = permittivity of free space

Volume Charge density for the given case is given by the formula:

$\rho_{v} = \frac{Total\ charge, q}{Volume of cube, V}$ (2)

Volume of cube, $V = a^{3}$

Thus

$V = (8.0\times 10^{- 2})^{3} = 5.12\times 10^{- 4}\ m^{3}$

Thus from eqn (2), the total charge is given by:

$q = \rho_{v}V = 40\times {- 9}\times 5.12\times 10^{- 4}$

$q = 2.048\times 10^{-11}\ F = 20.48\ pF$

Now, substitute the value of 'q' in eqn (1):

$\phi = \frac{2.048\times 10^{-11}}{8.85\times 10^{- 12}} = 2.314\ Nm^{2}/C$

5 0

2 years ago

According to Dr. paul Narguizian professor of Biology and Science Education at California State University, ______ are generaliz

Mazyrski [523]

Answer:

I believe the correct answer would be A :)

Explanation:

3 0

1 year ago

Heat is allowed to flow from the heat source of a heat engine at 425 K to a cold sink at 313 K. What is the efficiency of the he

olga2289 [7]

I assume here that the engine operates following a Carnot cycle, which achieves the maximum possible efficiency.

Under this assumption, the efficiency of the engine (so, the efficiency of the Carnot cycle) is given by
$\eta = 1- \frac{T_{cold}}{T_{hot}}$
where
$T_{cold}$ is the cold temperature
$T_{hot}$ is the hot temperature

For the engine in our problem, the cold temperature is 313 K while the hot temperature is 425 K, so the effiency of the engine is
$\eta=1- \frac{313 K}{425 K}=0.264 = 26.4 \%$

3 0

2 years ago

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