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3 years ago

13

If a Stone with an of original velocity of zero is falling from a ledge and takes eight seconds to hit the ground what is the fi

nal velocity of the stone

1 answer:

DaniilM [7]3 years ago

3 0

Let t=time to reach the ground=8 secs, g= acceleration of gravity. The speed v on reaching the ground is gt=8g=78.4 m/s where g=9.8 m/s/s approx.

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How does the way that matter cycles through an ecosystem differ from the way that energy flows?

guapka [62]

Unlike the one-way flow of energy, matter is recycled within and between ecosystems. Every living organism needs nutrients to build tissues and carry out essential life functions.

7 0

3 years ago

Tarzan (who has mass 80.0 kg) is running across the jungle floor with speed 7.00 m/s as

Lesechka [4]

<u>We are given:</u>

Mass of Tarzan before swinging = 80 kg

Mass of Tarzan when swinging = 80 + 15 = 95 kg

Velocity of Tarzan = 7 m/s

The height of the rock Tarzan's monkey is sitting on = 3 m

__________________________________________________________

<u>Momentum of Tarzan before swinging:</u>

We know that:

Momentum = Mass*Velocity

Momentum = 80 * 7

Momentum = 560 kg m/s

__________________________________________________________

<u>Speed of Tarzan after grabbing the bananas:</u>

The momentum of Tarzan will remain the same but his mass will increase

So, Since Momentum = New Mass* velocity

560 = 95 * v [where v is the velocity of Tarzan]

v = 5.9 m/s

<u>__________________________________________________________</u>

<h3><u>Finding the Initial and Final KE and PE:</u></h3>

<em>Here, KE = Kinetic Energy and PE = Potential Energy</em>

<u>Initial and Final KE:</u>

We know that KE = 1/2*(mv²)

<u>Initial KE:</u>

Initial KE = 1/2*(mv²) [where v is the velocity after picking the bananas]

Initial KE = 1/2*(95*5.9²)

Initial KE = 1653.5 Joules

<u>Final KE:</u>

Final KE = 1/2*(mv²)

<em>[where v is the velocity at the maximum point of the swing]</em>

Since Tarzan will be at rest at the maximum point of the swing, v = 0 m/s

Final KE = 1/2*(95*0²)

Final KE = 0 Joules

<u>Initial and Final PE:</u>

We know that:

PE = mgh

<em>[where g is the acceleration due to gravity and h is the height]</em>

<u>Initial PE:</u>

Since the height of Tarzan from the ground was 0 m at the beginning of the swing, h = 0

Initial PE = 95*10*0

Initial PE = 0 Joules

<u>Final PE:</u>

Let the maximum height of Tarzan be h m

Final PE = 95*10*h

Final PE = 950(h)

__________________________________________________________

<h3><u>Finding the maximum height Tarzan will reach:</u></h3>

<em>Here, KE = Kinetic Energy and PE = Potential Energy</em>

From the law of conservation of momentum, we know that:

Initial KE + Initial PE = Final KE + Final PE

Replacing the variables:

1653.5 + 0 = 0 + 950h

1653.5 = 950h

h = 1653.5/950 [dividing both sides by 950]

h = 1.74 m

Therefore, the maximum height reached by Tarzan is 1.74 m

but since his monkey is sitting 3 m high, he will NOT be able to reach his monkey

6 0

3 years ago

Which best describes how energy changes form in a car's engine?

andrezito [222]

Answer:

Multiple transformations occur because the chemical energy of the fuel is changed to several forms of energy

Explanation:

In a car engine, multiple energy transformation takes place. The chemical energy storef in fuel is transformed into mechanical energy which helps move the wheels of the vehicle.

The mechanical energy can also be transformed into electrical energy through a sort of dynamo system in vehicles. Stereo players use the electrical energy to produce sound.

We see that multiple energy conversions are common in a motor car.

6 0

3 years ago

Read 2 more answers

A family drives north for 30km then turns east for 20km. The family then decided to turn west for 5km before finally stopping to

salantis [7]

Answer:

A

Explanation:

They drove 30km north. The displacement adds up to 25km therefore making the distance greater

Hope this helps!

6 0

3 years ago

A body weights 50 N in air and 45 N when wholly immersed in water calculate (i) the loss in weight of the body in water (ii) the

Lelechka [254]

Answer:

$difference \: in \: weight = 150n - 100n = 50n$

Now,buyantant force

$difference \: in \: weight \: = volume(body) \times density \: of \: water \: \times g$

so;

$50 = {v}^{b} \times 1 \times {10}^{3} \times 9.8m {s}^{2}$

${v}^{b} = \frac{50}{1000 } \times 9.8$

$= \frac{50}{9800}$

$= 0.0051$

Now,

$mass \: in \: air \: = 150n = \frac{150}{9.8kg}$

$density = \frac{weght}{volume}$

$= \frac{150}{0.0051} \times 9.8 \\ x = 3000$

And now,

$specific \: density \: = \frac{density of \: the \: body}{density \: of \: water}$

$= \frac{3000}{1000}$

$= 3$

Hence that,specific density of a given body is 3

please mark me as brainliest, please

3 0

2 years ago