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4 years ago

Which event is an example of a contact force?

Physics

1 answer:

Scorpion4ik [409]4 years ago

4 0

Answer:

D. a person pulling a sled.

Explanation:

contact force only occurs when something directly comes in contact with another object.

a. is wrong because that is called magnetic force.

b. gravitational force

c. is an electrical force

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Witch unit is used to measure mass in the metric system

Alecsey [184]

The gram (g)
a nickel weighs 5 grams, and a raisin weighs approximately 1 gram.
There is also the kilogram(kg), or 1000 grams

6 0

3 years ago

Read 2 more answers

A 50 mm diameter steel shaft and a 100 mm long steel cylindrical bushing with an outer diameter of 70 mm have been incorrectly s

BARSIC [14]

Answer:

The axial force is $P = 15.93 k N$

Explanation:

From the question we are told that

The diameter of the shaft steel is $d = 50mm$

The length of the cylindrical bushing $L =100mm$

The outer diameter of the cylindrical bushing is $D = 70 \ mm$

The diametral interference is $\delta _d = 0.005 mm$

The coefficient of friction is $\mu = 0.2$

The Young modulus of steel is $207 *10^{3} MPa (N/mm^2)$

The diametral interference is mathematically represented as

$\delta_d = \frac{2 *d * P_B * D^2}{E (D^2 -d^2)}$

Where $P_B$ is the pressure (stress) on the two object held together

So making $P_B$ the subject

$P_B = \frac{\delta _d E (D^2 - d^2)}{2 * d* D^2}$

Substituting values

$P_B = \frac{(0.005) (207 *10^{3} ) * (70^2 - 50^2))}{2 * (50) (70) ^2 }$

$P_B = 5.069 MPa$

Now he axial force required is

$P = \mu * P_B * A$

Where A is the area which is mathematically evaluated as

$\pi d l$

So $P = \mu P_B \pi d l$

Substituting values

$P = 0.2 * 5.069 * 3.142 * 50 * 100$

$P = 15.93 k N$

8 0

4 years ago

Deer ticks can carry both Lyme disease and human granulocytic ehrlichiosis (HGE). In a study of ticks in the Midwest, it was fou

tiny-mole [99]

Answer:

a)0.024

b)0.148

Explanation:

Let 's represent the set of deer ticks Carrying Lyme disease with L and the set of deer ticks carrying Human Granulocytic Ehrlichiosis with H

Given:

P(L) = 0.16

P(H) = 0.10

P(L n H) = 0.1 ·P( L u H )

Hence, P( L u H) = 10 ·P( L nH)

(a)

Hence. using the equation. P(L U H) = P(L) + P(H) - P(L n H)

Hence, 10 · P(L n H ) = 0.16 + 0.1 - P(L n H )

Hence, 11 · P(L n H) = 0.16 + 0.1 = 0.26

Hence, P(L n H) = 0.26/11=0.024

(b)

We know that condition probability P(H ║ L) = p(L n H)/P(L)

hence, P(H ║ L) =(0.26/11)/0.16 =0.148

3 0

3 years ago

Which equation represents a neutralization reaction?

elixir [45]

B acid + base → water + salt

Explanation:

The best equation that represents a neutralization reaction is:

acid + base → water + salt

In a neutralization reaction, an acid reacts with a base to produce salt and water only.

Here, hydrogen combines with hydroxide to form water.

Titration is usually used to carry out this reaction in the laboratory.

An indicator is added to the base and at end the color of the reaction changes.

At this point the acids have completely been neutralized with the base.

Learn more:

Neutralization brainly.com/question/4455839

#learnwithBrainly

5 0

3 years ago

The x and y components of vector S are -30.0 m and +40.0 m, respectively. Find the magnitude of S and the angle between the dire

34kurt

Answer:

The given vector can be represented in unit vector as

$\overrightarrow{w}=-30\widehat{i}+40\widehat{j}$

The magnitude of any vector $\overrightarrow{r}=u\widehat{i}+v\widehat{j}$ is given by

$|w|=\sqrt{u^{2}+v^{2}}$

Applying values we get

$|w|=\sqrt{-30^{2}+40^{2}}\\\\|r|=50$

We know that positive x axis in vertorial form is represented as

$\overrightarrow{r}=\widehat{i}$

taking dot product of both the vector's we get

$\overrightarrow{r}.\overrightarrow{w}=|r||w|cos(\theta )\\\\\therefore cos(\theta )=\frac{(-30\widehat{i}+40\widehat{j}).\widehat{i}}{50}\\\\\therefore \theta =cos^{-1}(\frac{-30}{50})=126.86^{o}$

5 0

3 years ago

Read 2 more answers