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3 years ago

17. A skateboard has a mass of 3.2 kg. If it slips out from a skateboarder and has

Physics

1 answer:

Akimi4 [234]3 years ago

6 0

<h2>Book will hit the foot with force 21.8 N</h2>

Explanation:

The momentum of any object = m v

here m is the mass of body and v is its velocity

Thus momentum P = 3.2 x 1 = 3.2 kg-m

As the book is falling freely , so it will fall with and acceleration g

The force exerted by it is = m g

Thus force = 2.18 x 10 = 21.8 N

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Please fast answerrr thank you

Vedmedyk [2.9K]

Answer:

50J

Explanation:

At the top you have(A)

KE_a = O

PE_a = 100J

KE + PE = 100J

At the bottom you have (C)

KE_c= 100J

PE_c=0J

KE+PE = 100J

At point C:

You are at half the height.

We know that at H, PE =100J

PE_c = mgH

At C,

PE_c= mg (H/2) *at half the height

*m and g stay the same

Intuitively, the higher you are, the more potential energy you have.

If you decrease the height by a half, your PE will also decrease

At A:

PE_a / (mg) = H

At B:

PE_b / (mg) = H/2

to also get H on the right hand side, multiply by 2

2 (PE_b/ (mg))= H

2PE_b / (mg) = H

Ok, now that we have set up 2 equations (where H is isolated), find PE at B

AT A = AT B *This way you are saying that H = H (you compare both equations)

PE_a / (mg) = 2x PE_b / (mg)

*mg are the same for both cancel them (you can do that because of the = sign)

PE_a = 2PE_b

We know that PE_a = 100J

100J/2 = PE_b

PE at b = 50J

**FIND KE at b

We know that

KE_b + PE_b is always 100J

100J = 50J + KE_b

KE_b = 50J

4 0

2 years ago

According to a general theory of crime, individuals who engage in crime are also likely to engage in other risky behaviors, for

babymother [125]

Answer:

construct validity

Explanation:

According to my research on studies conducted by various psychologists, I can say that based on the information provided within the question it seems that the researcher is using construct validity. This is the act of measuring or validating what the extent to which a claim is true. In this situation since the claim states that people involved in crimes tend to do speed and drugs, then the researcher compares the criminals responses to those areas to test the validity of the claim.

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.

6 0

3 years ago

Which of these best describes heat transfer through conduction? A) Heat transfer as electrons are excited in atoms. B) Heat tran

Setler79 [48]

I'd go for D here. It also fits in with the idea of thermal expansion - as something is heated up, molecules vibrate and maybe collide. they vibrate with bigger amplitudes, so taking up more space, so expanding. maybe

7 0

3 years ago

Read 2 more answers

Find the value of F1 + F2 + F3.

Dovator [93]

Answer:

F = 0.78[N]

Explanation:

The given values correspond to forces, we must remember or take into account that the forces are vector quantities, that is, they have magnitude and direction. Since we have two X-Y coordinate axes (two-dimensional), we are going to decompose each of the forces into the X & y components.

For F₁

$F_{y}=2[N]$

For F₂

$F_{x}=2*cos(60)\\F_{x}=1[N]\\F_{y}=-2*sin(60)\\F_{y}=-1.73[N]$

For F₃

$F_{x}=-1*sin(60)\\F_{x}=-0.866[N]\\F_{y}=1*cos(60)\\F_{y}=0.5 [N]$

Now we can sum each one of the forces in the given axes:

$F_{x}=1-0.866=0.134[N]\\F_{y}=2-1.73+0.5\\F_{y}=0.77[N]$

Now using the Pythagorean theorem we can find the total force.

$F=\sqrt{(0.134)^{2} +(0.77)^{2}}\\F= 0.78[N]$

8 0

3 years ago

How Does Earth's gravitational force field act on objects that aren't touching Earth's surface?

natali 33 [55]

Answer:

Explanation:

Gravity is a field force since the earth does not have to actually “touch” an object to pull it toward the earth. A magnetic force is a field force that attracts or repels another magnet. Likewise, electric charges cause attracting or repelling forces without actual contact between the charges

8 0

2 years ago