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2 years ago

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As the boat in which he is riding approaches a dock at 3.0 m/s, Jasper stands up in the boat and jumps toward the dock. Jasper a

pplies an average force of 800. newtons on the boat for 0.30 seconds as he jumps.
a. How much momentum does Jasper’s 80.-kilogram body have as it lands on the dock?
b. What is Jasper's speed on the dock?

1 answer:

Annette [7]2 years ago

5 0

Im pretty sure it’s a because it makes more sense you know?.

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saul85 [17]

Answer:

Haha

Explanation:

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3 years ago

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

$\mu_k m_b g cos 25 *d$

So

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

Substituting values

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

So

$d = 0.313 \ m$

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3 years ago

Does specific heat change with mass?

ch4aika [34]

Heat<span> capacity ( C ) </span>does change with mass<span>. However, </span>specific heat<span> is the </span>heat<span>capacity per unit </span>mass<span> ( c=Cm ). Therefore if you double the amount of </span>mass<span> in your system, you've doubled its </span>heat<span> capacity, but you've kept the </span>specific heat<span> the same. ... </span>Specific<span> gravity is another such quantity.</span>

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3 years ago

A body weighing 250 grams was dropped from a helicopter flying at an altitude of 100 meters. Determine the potential energy of t

kogti [31]

Answer:

the potential energy of this body is 245 J.

Explanation:

Given;

mass of the body, m = 250 g = 0.25 kg

height from which the body was dropped, h = 100 m

acceleration due to gravity, g = 9.8 m/s²

The potential energy of this body is calculated as;

P.E = mgh

substitute the given values and solve for the potential energy of this body;

P.E = 0.25 x 9.8 x 100

P.E = 245 J.

Therefore, the potential energy of this body is 245 J.

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2 years ago

Which state of matter has a definite volume but no definite shape

a_sh-v [17]

The answer is liquid.

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3 years ago