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3 years ago

A wooden beam with a mass of 10.8 kg is supported by vertical supports

Physics

1 answer:

blondinia [14]3 years ago

7 0

Answer:

Force from the support closest = 79.8 N

Force from the support furthest = 61.9 N

Explanation:

Let's say the length of the beam is L. Let's say A is the near end of the beam and B is the far end of the beam.

Draw a free body diagram. There are four forces on the beam:

Reaction force Ra at the near end (0),

Reaction force Rb at the far end (L),

Weight force of the beam Mg at the center (L/2),

Weight force of the book mg at L/4 from A.

Sum of torques at A:

∑τ = Iα

Rb (L) − Mg (L/2) − mg (L/4) = 0

Rb (L) = Mg (L/2) + mg (L/4)

Rb = ½ Mg + ¼ mg

Rb = (½ M + ¼ m) g

Rb = (½ (10.8 kg) + ¼ (3.66 kg)) (9.8 m/s²)

Rb = 61.9 N

Sum of forces in the y direction:

∑F = ma

Ra + Rb − Mg − mg = 0

Ra = Mg + mg − Rb

Ra = (M + m) g − Rb

Ra = (10.8 kg + 3.66 kg) (9.8 m/s²) − 61.9 N

Ra = 79.8 N

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Ymorist [56]

Answer:

1. As rocket mass increases, acceleration decreases.

2. The inverse of the mass of the boat.

Explanation:

1. Newton's second law of motion states;

F = ma

where F is the force applied, m is the mass and a is the acceleration.

Therefore, increasing the mass of a rocket increases its weight which would reduce its acceleration provided that the force is constant. Thus, as rocket mass increases, acceleration decreases.

2. The slope of the graph can be expressed as;

From Newton's second law,

F = ma

Slope = (Δa) ÷ (ΔF)

Slope = $\frac{a}{F}$

⇒ $\frac{1}{m}$ = $\frac{a}{F}$

Therefore, the slope of the graph is the reciprocal of the mass of the boat.

7 0

3 years ago

A parallel-plate capacitor with plates of area 360 cm2 is charged to a potential difference V and is then disconnected from the

Softa [21]

Answer:

$Q=3.9825\times 10^{-9} C$

Explanation:

We are given that a parallel- plate capacitor is charged to a potential difference V and then disconnected from the voltage source.

1 m =100 cm

Surface area =S= $\frac{360}{10000}=0.036 m^2$

$\Delta d=0.8 cm=0.008 m$

$\Delta V=100 V$

We have to find the charge Q on the positive plates of the capacitor.

V=Initial voltage between plates

d=Initial distance between plates

Initial Capacitance of capacitor

$C=\frac{\epsilon_0 S}{d}$

Capacitance of capacitor after moving plates

$C_1=\frac{\epsilon_0 S}{(d+\Delta d)}$

$V=\frac{Q}{C}$

Potential difference between plates after moving

$V=\frac{Q}{C_1}$

$V+\Delta V=\frac{Q}{C_1}$

$\frac{Qd}{\epsilon_0S}+100=\frac{Q(d+\Delta d)}{\epsilon_0S}$

$\frac{Q(d+\Delta d)}{\epsilon_0 S}-\frac{Qd}{\epsilon_0S}=100$

$\frac{Q\Delta d}{\epsilon_0 S}=100$

$\epsilon_0=8.85\times 10^{-12}$

$Q=\frac{100\times 8.85\times 10^{-12}\times 0.036}{0.008}$

$Q=3.9825\times 10^{-9} C$

Hence, the charge on positive plate of capacitor= $Q=3.9825\times 10^{-9} C$

6 0

3 years ago

Which term below describes a measurement of how hard an object pushes against a surface?

Scilla [17]

I hope the answer is D. Pressure

8 0

3 years ago

Read 2 more answers

To balance a chemical equation we use______. -coefficients -subscripts

Vitek1552 [10]

Answer:

Coefficients

Explanation:

Coefficients are used to balance chemical equations.
According to the law of conservation of mass, the mass of the reactants in a chemical equation should be equivalent to the mass of the products.
The conservation of mass is achieved in chemical equations is achieved through balancing chemical equations.
Balancing chemical equations is a try and error of putting appropriate coefficients to the reactants or products to ensure that the number of atoms of each element are equal on the side of the reactants and that of products.

3 0

3 years ago

A man climbs a wall that has a height of 8.4 meters and gave the potential energy of 4620 joules. His mass is about_____ kilogra

Dmitrij [34]

Gravitational potential energy = mass x acceleration due to gravity x height
GPE=mgh
4620=mx9.81x8.4
4620/(9.81x8.4)=m=56.1 kg

7 0

3 years ago