An electric hoist does 56,447 J of work in raising 115 kg load. How high (in meters) was the load lifted?

Figure 8-56 shows a solid, uniform cylinder of mass 7.00 kg and radius 0.450 m with a light string wrapped around it. A 3.00-N t

AVprozaik [17]

Answer:

a) The cylinder has an angular acceleration of 3.810 radians per square second, b) The frictional force has a magnitude of 9 newtons and has the same direction of tension force.

Explanation:

The external force exerted on string creates a tension force that tries to move the cylinder in translation, but it is opposed by the friction force between cylinder and ground that generates rolling on cylinder. The Free Body Motion on cylinder-string system is presented below as attachment. Given that cylinder is a rigid body in planar motion, two equations of equilibrium for translation and an equation of equilibrium for rotation are needed to represent the system, which are now described:

$\Sigma F_{x} = T + f = M\cdot R\cdot \alpha$

$\Sigma F_{y} = N - M\cdot g = 0$

$\Sigma M_{G} = (T-f)\cdot R = I_{G}\cdot \alpha$

Where:

$T$ - Tension, measured in newtons.

$f$ - Friction force, measured in newtons.

$M$ - Mass of the cylinder, measured in kilograms.

$R$ - Radius of the cylinder, measured in meters.

$\alpha$ - Angular acceleration, measured in radians per square second.

$N$ - Normal force from ground exerted on cylinder, measured in newtons.

$g$ - Gravitational acceleration, measured in meters per square second.

$I_{G}$ - Moment of inertia of the cylinder with respect to its center of mass, measured in kilogram-square meters.

The moment of inertia of the cylinder is:

$I_{G} = \frac{1}{2}\cdot M\cdot R^{2}$

a) The angular acceleration is determined by solving on first and third equation after eliminating friction force:

$f = M\cdot R \cdot \alpha - T$

$(T-M\cdot R\cdot \alpha+T) \cdot R = I_{G}\cdot \alpha$

$2\cdot T\cdot R = (I_{G} + M\cdot R^{2})\cdot \alpha$

$\alpha = \frac{2\cdot T\cdot R}{I_{G}+M\cdot R^{2}}$

$\alpha = \frac{2\cdot T \cdot R}{\frac{1}{2}\cdot M\cdot R^{2}+M\cdot R^{2} }$

$\alpha = \frac{4\cdot T}{3\cdot M\cdot R}$

If $T = 3\,N$ , $M = 7\,kg$ and $R = 0.45\,m$ , then:

$\alpha = \frac{4\cdot (3\,N)}{(7\,kg)\cdot (0.45\,m)}$

$\alpha = 3.810\,\frac{rad}{s^{2}}$

The cylinder has an angular acceleration of 3.810 radians per square second.

b) The magnitude of the frictional force can be determined with the help of the following expression:

$f = M\cdot R \cdot \alpha - T$

Given that $T = 3\,N$ , $M = 7\,kg$ , $R = 0.45\,m$ and $\alpha = 3.810\,\frac{rad}{s^{2}}$ , the magnitude of the friction force is:

$f = (7\,kg)\cdot (0.45\,m)\cdot \left(3.810\,\frac{rad}{s^{2}} \right)-3\,N$

$f = 9\,N$

The frictional force has a magnitude of 9 newtons and has the same direction of tension force.

5 0

4 years ago

With a cruising speed of 2.30 x 10 km/h, the French supersonic pas-

miss Akunina [59]

Answer:

so you have a cruising speed of 2.30* 10km/h, the french supersonic pas- senger jet cocorde.

Explanation:

accelerates at -5.80m/s2,how far does it travel betwween the time it hands and the times it comes to a complete stop.Thanks friends.

7 0

3 years ago

Please Help!!!

Alecsey [184]

The statement that best describes the types of bonds shown in the diagram is a covalent bond; the hydrogen atom’s single electron is being shared with the chlorine atom, therefore the correct answer is the option B

<h3>What is a covalent bond?</h3>

When two similar or dissimilar atoms form bonds with each other by sharing their valence electron the bond is known as the covalent bond.

The ionic bond is the result of the transfer of the electrons

Ionic bonds are formed between the pair of one electronegative atom and an electropositive atom.

As shown in the diagram there is sharing of the electrons between the hydrogen and the chlorine atom, and we know that covalent bonds are formed by the sharing of the electrons

Since the diagram's covalent bonds are best described by the statement that the hydrogen atom's single electron is shared with the chlorine atom, option B is the right response.

Learn more about covalent bonds from here

brainly.com/question/19382448

#SPJ2

3 0

1 year ago

Read 2 more answers

A wall clock has a minute hand with a length of 0.53 m and an hour hand with a length of 0.26 m. Take the center of the clock as

ollegr [7]

Answer:

a =1.61 × 10⁻⁶ m/s²

Explanation:

given,