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2 years ago

PLS HELP

Physics

2 answers:

Amanda [17]2 years ago

7 0

V(final) = V(initial) + a•t

Take the numbers you know, pluggum in, and you should get 3.836 m/s .

Note: This is just the final speed. Without any direction information, there's no way to find the velocity.

Zepler [3.9K]2 years ago

5 0

Answer:

hmm first add 32 plus 53 plus 12 trust me and when you get the answer subtract 25

Explanation:

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A 20-kg block is held at rest on the inclined slope by a peg. A 2-kg pendulum starts at rest in a horizontal position when it is

gregori [183]

Complete Question

The diagram of this question is shown on the first uploaded image

Answer:

The distance the block slides before stopping is $d = 0.313 \ m$

Explanation:

The free body diagram for the diagram in the question is shown

From the diagram the angle is $\theta = 25 ^o$

$sin \theta = \frac{h}{d}$

Where $h = h_b - h_a$

So $d sin \theta = h_b - h_a$

From the question we are told that

The mass of the block is $m = 20 \ kg$

The mass of the pendulum is $m_p = 2 \ kg$

The velocity of the pendulum at the bottom of swing is $v_p = 15 m/s$

The coefficient of restitution is $e =0.7$

The coefficient of kinetic friction is $\mu _k = 0.5$

The velocity of the block after the impact is mathematically represented as

$v_2 f = \frac{m_b - em_p}{m_b + m_p} * v_2 i + \frac{[1 + e] m_1}{m_1 + m_2 } v_p$

Where $v_2 i$ is the velocity of the block before collision which is 0

$= \frac{20 - (0.7 * 2)}{(2 + 20)} * 0 + \frac{(1 + 0.7) * 2 }{2 + 20} * 15$

Substituting value

$v_2 f = 2.310\ m/s$

According to conservation of energy principle

The energy at point a = energy at point b

So $PE_A + KE _A = PE_B + KE_B + E_F$

Where

$PE_A$ is the potential energy at A which is mathematically represented as

$PE_A = m_b gh_a$ = 0 at the bottom

$KE _A$ is the kinetic energy at A which is mathematically represented as

$K_A = \frac{1}{2} m_b * v_2f^2$

$PE_B$ is the potential energy at B which is mathematically represented as

$PE_B = m_b gh$

From the diagram $h = h_b -h_a$

$PE_B = m_b g(h_b - h_a)$

$KE _B$ is the kinetic energy at B which is 0 (at the top )

Where is $E_F$ is the workdone against velocity which from the diagram is

$\mu_k m_b g cos 25 *d$

$\frac{1}{2} m_b v_2 f^2 = m_b g h_b + \mu_k m_b g cos \25 * d$

Substituting values

$\frac{1}{2} * 20 * 2.310^2 = 20 * 9.8 * d sin(25) + 0.5* 20 * 9.8 * cos 25 * d$

$d = 0.313 \ m$

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3 years ago

The compass uses a pendulous system to improve?

ivanzaharov [21]

The compass is designed and developed to use a pendulous system to improve horizontality.

<h3>What is a compass?</h3>

A compass can be defined as a scientific instrument that contains a magnetized pointer, which is used to show and indicate the following four (4) main cardinal directions:

North (N)

South (S)

West (W)

East (E)

Basically, the compass is a scientific instrument that's designed and developed to use a pendulous system to improve horizontality.

Read more on compass here: brainly.com/question/11165627

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A dog is running at 15 m/s and then slows down to 10 m/s. It takes him two seconds to do this. What is the dog's acceleration

OLga [1]

Explanation:

a = (Vf-Vi)/t

= (10m/s - 15m/s)/2s

a = -5 / 2 m/s^2

• so the dog diaccelerate at the rate of 5/2 m/s^2

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3 years ago

the speed of light in a certain medium is 0.6c. find critical angle , if the index of refraction is 1.67

baherus [9]

Answer:

$\theta_c = 36.78^o$

Explanation:

The relationship between the refractive index and the critical angle is given as follows:

$\eta = \frac{1}{Sin\ \theta_c} \\\\Sin\ \theta_c = \frac{1}{\eta}\\\\\theta_c = Sin^{-1}(\frac{1}{\eta} )$

where,

η = refractive index = 1.67

θc = critical angle =?

Therefore,

$\theta_c = Sin^{-1}(\frac{1}{1.67} )$

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Which statement about the effects of medium on the speed of a mechanical wave is true?

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