All categories

3 years ago

If you are pushing a table with a force of 5 newtons what is the force pushing back on you

1 answer:

4 0

The force pushing back to you would be 5 newtons as Newtons 3rd law says that every action force has an opposite but equal reaction force acting upon it (if i remember correctly )

You might be interested in

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

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

$d = 0.313 \ m$

6 0

3 years ago

A wind turbine has a total input power of 2 500 kW.

Sonbull [250]

Answer:

Output power = 500 KW

Explanation:

Given the following data;

Efficiency = 20%

Input power = 2500 KW

To find the output power;

$Efficiency = \frac {Out-put \; power}{In-put \; power} * 100$

Substituting into the equation, we have;

LET Output power = OP

$20 = \frac {OP}{2500} * 100$

Cross-multiplying, we have;

$20 * 2500 = OP * 100$

$50000 = OP * 100$

$OP = \frac {50000}{100}$

Output power = 500 KW

6 0

2 years ago

Which set of shapes contains members that are always similar to one another?

Colt1911 [192]

<span>The correct answer is option C. i.e.Equilateral triangles. All equilateral triangle have equal sides. Due to this these set of shapes will always be similar. Similarity in the sense that only the size of the triangles can change to large or smaller but the shape will be be similar always.</span>

3 0

2 years ago

True or false? Once the sun explodes, the whole solar system will go with it.

liberstina [14]

True. That is how powerful the sun is. But it will explode in only about 5 billion years.

6 0

3 years ago

Which statement about van der Waals forces is true?

kobusy [5.1K]

The answer is A. When the forces are weaker, they will not be able to hold the particles of the substances together; therefore, the substance will be observed as being volatile.

3 0

3 years ago

Read 2 more answers