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4 years ago

A custodial pushes a crate across the gym floor. What are the forces used

Physics

1 answer:

Galina-37 [17]4 years ago

6 0

Answer:

when a custodian pushes a large crate across the gym floor, forces acting on the crate are the one applied by the custodian, frictional force acting in the opposite direction of motion acting between the surface of crate and floor and reaction force (normal force) acting in upward direction normal to the surface

Explanation:

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Two identical traveling waves, moving in the same direction, are out of phase by π/5.0 rad. What is the amplitude of the resulta

andreev551 [17]

Answer:

Therefore the amplitude of the resultant wave is $=0.95 y_m$

Explanation:

The equation of wave:

y=A sin (kx-ωt)

For wave 1:

y₁=A sin (kx-ωt) = $y_{m}$ sin (kx-ωt)

For wave 2:

y₂=A sin (kx-ωt+Φ) = $y_{m}$ sin (kx-ωt+Φ)

Where A= amplitude= $y_m$

The angular frequency $\omega=\frac{2\pi}{T}$

$k=\frac{2\pi}{\lambda}$ , $\lambda$ = wave length.

t= time

T= Time period

$\phi$ = phase difference = $\frac{\pi}{5}$

The resultant wave will be

y = y₁ + y₂

= $y_m$ sin (kx-ωt) + $y_m$ sin (kx-ωt+Φ)

$=y_m$ {sin (kx-ωt) + sin (kx-ωt+Φ)}

$=y_m\ sin(\frac{kx-\omega t +\phi + kx-\omega t }2)\ cos(\frac{kx-\omega t +\phi -kx+\omega t}2)$

$=y_m\ sin({kx-\omega t +\frac\phi 2)\ cos(\frac{\phi }2)$

$=y_m\ cos(\frac{\phi }2) sin({kx-\omega t +\frac\phi 2)$

Therefore the amplitude of the resultant wave is

$=y_m\ cos(\frac{\phi }2)$

$=y_m\ cos(\frac{\pi }{10})$

$=0.95 y_m$

6 0

4 years ago

A 3-kg mass is in free fall. What is the velocity of the mass after 7 seconds??

dmitriy555 [2]

69 ms. I hope that helps

6 0

3 years ago

A 7.8-kg solid sphere, made of metal whose density is 2500 kg/m3, is suspended by a cord. When the sphere is immersed in water (

Klio2033 [76]

Answer:

Density of the liquid = 1470.43 kg/m³

Explanation:

Given:

Mass of solid sphere(m) = 6.1 kg

Density of the metal = 2600 kg/m³

Thus volume of the liquid :

Volume of the sphere = 6.1 kg/2600 kg/m³ = 0.002346 m³

The volume of water displaced is equal to the volume of sphere (Archimedes' principle)

Volume displaced = 0.002346 m³

Buoyant force =

Where

is the density of the fluid

g is the acceleration due to gravity

V is the volume displaced

The free body diagram of the sphere is shown in image.

According to image:

Acceleration due to gravity = 9.81 ms⁻²

Tension force = 26 N

Applying in the equation to find the density of the liquid as:

Thus, the density of the liquid = 1470.43 kg/m³

3 0

2 years ago

The total mass of the train and its passengers is 750000kg. The train is traveling at a speed of 84m/s. The driver applies the b

fiasKO [112]

Answer:

|F| = 393750 N

Explanation:

Given that,

Total mass of the train, m = 750000 kg

Initial speed, u = 84 m/s

Final speed, v = 42 m/s

Time, t = 80 s

We need to find the net force acting on the train. The formula for force is given by :

F = ma

$F=\dfrac{m(v-u)}{t}\\\\F=\dfrac{750000\times (42-84)}{80}\\\\F=-393750\ N$

So, the magnitude of net force is 393750 N.

4 0

3 years ago

Germanium to which 1024 m-3 Ga atoms have been added is an extrinsic semiconductor at room temperature, and virtually all the Ga

Svetlanka [38]

Answer:

Electrical Conductivity is 3200 $(\Omega m)^{-1}$

Solution:

As per the question:

$N_{A} = 10^{24}\ m^{- 3}\ Ga\ atoms$

Mobility of electrons, $\mu_{e} = 0.26\ m^{2}/ Vs$

Mobility of holes, $\mu_{h} = 0.020\ m^{2}/ Vs$

Charge, Q = $1.6\times 10^{- 19}\ C$

Now,

The formula for the conductivity is given by:

$\sigma = N_{A}Q\mu_{h}$

$\sigma = 10^{24}\times 1.6\times 10^{- 19}\times 0.020} = 3200(\Omega m)^{-1}$

5 0

3 years ago