What units are vector units

A 0.41-kg particle has a speed of 5.0 m/s at point A and kinetic energy of 8.5 J at point B. (a) What is its kinetic energy at A

Kipish [7]

<u>Answer:</u>

A)The kinetic energy at a point A when a particle of .41 kg moves at a speed of 5.0 m/s is 5.125 J.

B)The speed at point B of the particle of .41 kg with Kinetic Energy 8.5 J is 6.44 m/s.

C)The total Work done by the particle is 3.375 J.

<u>A)Explanation </u>

From the given statements, we know

Mass (m) = 0.41 kg

Velocity = 5.0 m/s

As we know Kinetic Energy (KE) = $\frac{1}{2} \text { mass } \times \text { velocity }^{2}$

Substituting the values in the above equation, we find

Kinetic Energy (KE) = $\frac{1}{2} \text { mass } \times \text { velocity }^{2}$

$\frac{1}{2} \times 0.41 \times 5^{2}$ = 5.125 joule

(b) Explanation

From the given statements, we know

Mass (m) = 0.41 kg

Kinetic Energy (KE) = 8.5 J

As we know Kinetic Energy (KE) = $\frac{1}{2} \text { mass } \times \text { velocity }^{2}$

Substituting the values in the above equation, we find

Kinetic Energy (KE) = $\frac{1}{2} \times 0.41 \times \mathrm{v}^{2}$ = 8.5 J

Or, $v^2$ = $\frac{8.5 \times 2}{0.41}$ = $\frac{8.5 \times 2}{0.41}$

Or, v = $\sqrt{\frac{17}{0.41}}$ =6.439 m/s ~ 6.44 m/s

(c) Explanation

From the above given statements, we know

Kinetic Energy at A = 5.125 J

Kinetic Energy at B = 8.5 J

As we know

Work Done = Change in Kinetic Energy (ΔKE)

So, Work Done (WD) = Kinetic Energy at B - Kinetic Energy at A

WD = (8.5 – 5.125) J = 3.375 J

4 0

3 years ago

What are 5 movements/skills that you are able to do because of your muscles?

Gnesinka [82]

One movement is walking. A skill we use is writing. Another movement is blinking. Another skill we use with muscles is typing. And finally, another skill we use muscles during is brushing your teeth.

7 0

3 years ago

Please answer my question!,

Karolina [17]

Answer:

Hope this helps! Mark as brainliest if liked thanks!

Explanation:

Your reasoning that the shadow is the shortest at mid-day is spot-on!

The wording of the question is the key to the answer. It says that the measurements were made in Summer. So this means that British Summer Time (BST) is being applied. BST is one hour ahead of Greenwich Mean Time and so what looks like 1pm is really 12 noon.

The safest sort of answer is to say that the shadow is shortest when the sun is at its highest point, and in this particular question that is at 1 pm because it is BST.

3 0

3 years ago

A hamster of mass 0.139 kg gets onto his 20.8−cm-diameter exercise wheel and runs along inside the wheel for 0.823 s until its f

Anna11 [10]

Explanation:

Given that,

Mass of the hamster, m = 0.139 kg

Diameter of the wheel, d = 20.8 cm

Radius, r = 10.4 m

Frequency of the wheel, f = 1 Hz

Time, t = 0.823 s

(a) There exist a relationship between the tangential and angular acceleration of the wheel. It is given by :

$a=\alpha \times r$

Since, $\alpha =\dfrac{\omega}{t}$

$a=\dfrac{\omega}{t} \times r$

$a=\dfrac{2\pi f}{t} \times r$

$a=\dfrac{2\pi \times 1}{ 0.823} \times 10.4\times 10^{-2}$

$a=0.793\ m/s^2$

(b) In radial direction, applying the second law of motion as :

$N-mg=ma$

a is the radial acceleration, $a=\dfrac{v^2}{r}$

$N=mg+ma$

$N=mg+m(\dfrac{v^2}{r})$

$N=mg+m(\dfrac{(r\omega)^2}{r})$

$N=mg+m\omega^2 r$

$N=m(g+\omega^2 r)$

$N=m(g+(2\pi f)^2 r)$

$N=0.139\times (9.8+(2\pi 1)^2\times 10.4\times 10^{-2})$

$N=1.93\ N$

Hence, this is the required solution.

8 0

4 years ago

Classify the items based on whether they are or are not matter.

Akimi4 [234]

Matter means the things that occupies space and has a mass.
So from this rule, we can identify the things given.
Toothpaste is a matter.
Happiness is not matter, it doesn't occupies space.
Gasoline is matter.
Sound doesn't have a mass, so it's not matter.
Bacteria is matter, it's one of the organisms in the 5 main kingdoms. It has a mass and it dies occupies space even its so small.
Cell is matter, because every living thing is made up of cells.

3 0

4 years ago

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