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3 years ago

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A girl drops a pebble from a high cliff into a lake far below. She sees the splash of the pebble hitting the water 2.00s later.

How fast was the pebble going when it hit the water?

1 answer:

Natali5045456 [20]3 years ago

3 0

Answer:

19.62 ms

Explanation:

t = Time taken = 2 s

u = Initial velocity

v = Final velocity

s = Displacement

a = Acceleration due to gravity = 9.81 m/s² (downward direction is taken as positive)

Equation of motion

$v=u+at\\\Rightarrow v=0+9.81\times 2\\\Rightarrow v=19.62\ m/s$

The speed of the pebble when it hit the water is 19.62 ms

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If two balls have the same volume,

Lena [83]

Here, we are required to find the relationship between balls of different mass(a measure of weight) and different volumes.

1. Ball A will have the greater density
2. Ball C and Ball D have the same density.
3. Ball Q will have the greater density.
4. Ball X and Y will have the same density

The density of an object is given as its mass per unit volume of the object.

Mathematically;.

Density = Mass/Volume.

For Case 1:

Va = Vb and Ma = 2Mb
D(b) = (Mb)/(Vb) and D(a) = 2(Mb)/Vb
Therefore, the density of ball A,
D(a) = 2D(b).
Therefore, ball A has the greater density.

For Case 2:

Vc = 3Vd,

Vd = (1/3)Vc

Md = (1/3)Mc

D(c) = (Mc)/(Vc) and D(d) = (1/3)Md/(1/3)Vd

D(c) = D(d).

Therefore, ball C and D have the same density

For Case 3:

Vp = 2Vq and Mp = Mq
D(p) = (Mq)/2(Vq) and D(q) = (Mq)/Vq
Therefore, the density of ball P is half the density of ball Q
Therefore, ball Q has the greater density.

For case 4:

Mx = (1/2)My
Vx = Vy

Therefore, Ball X and Ball Y have the same density.

Read more:

brainly.com/question/18110802

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2 years ago

The cornea behaves as a thin lens of focal length approximately 1.80 {\rm cm}, although this varies a bit. The material of which

spayn [35]

Answer:

The height of the image will be "1.16 mm".

Explanation:

The given values are:

Object distance, u = 25 cm

Focal distance, f = 1.8 cm

On applying the lens formula, we get

⇒ $\frac{1}{v} -\frac{1}{u} =\frac{1}{f}$

On putting estimate values, we get

⇒ $\frac{1}{v} -\frac{1}{(-25)} =\frac{1}{1.8}$

⇒ $\frac{1}{v} =\frac{1}{1.8} -\frac{1}{25}$

⇒ $v=1.94 \ cm$

As a result, the image would be established mostly on right side and would be true even though v is positive.

By magnification,

$m=\frac{v}{u}$ and $m=\frac{h_{1}}{h_{0}}$

⇒ $\frac{v}{u} =\frac{h_{1}}{h_{0}}$

⇒ $\frac{1.94}{25}=\frac{{h_{1}}}{15}$

⇒ ${h_{1}}=1.16 \ mm$

8 0

3 years ago

The carbon isotope 14C is used for carbon dating of archeological artifacts. 14C(mass 2.34×10−26kg) decays by the process known

Nookie1986 [14]

Answer:

2240.92365 m/s

Explanation:

$m_1$ = Mass of electron = $9.11\times 10^{−31}\ kg$

$v_1$ = Speed of electron = $5.7\times 10^7\ m/s$

$p_2$ = Neutrino has a momentum = $7.3\times 10^{-24}\ kg m/s$

M = total mass = $2.34\times 10^{-26}\ kg$

In the x axis as the momentum is conserved

$Mv_x=m_1v_1\\\Rightarrow v_x=\dfrac{m_1v_1}{M}\\\Rightarrow v_x=\dfrac{9.11\times 10^{−31}\times 5.7\times 10^7}{2.34\times 10^{-26}}\\\Rightarrow v_x=2219.10256\ m/s$

In the y axis

$Mv_y=p_2\\\Rightarrow v_y=\dfrac{p_2}{M}\\\Rightarrow v_y=\dfrac{7.3\times 10^{-24}}{2.34\times 10^{-26}}\\\Rightarrow v_y=311.96581\ m/s$

The resultant velocity is

$R=\sqrt{v_x^2+v_y^2}\\\Rightarrow R=\sqrt{2219.10256^2+311.96581^2}\\\Rightarrow R=2240.92365\ m/s$

The recoil speed of the nucleus is 2240.92365 m/s

3 0

3 years ago

Match each example to its type of energy.

PtichkaEL [24]

Solar energy - A

nuclear energy - B

fossil fuel energy - C

wind energy - D

geothermal energy - E

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3 years ago

The mass of the Sun is 1. 99 × 1030 kg. Jupiter is 7. 79 × 108 km away from the Sun and has a mass of 1. 90 × 1027 kg. The gravi

german

The gravitational force is s type of force that has the ability to attract any two objects having mass. The gravitational force will be $4.16\times10^{23}$ .

<h3>What is the gravitational force?</h3>

The gravitational force is s type of force that has the ability to attract any two objects with mass. Gravitational force tries to pull two masses towards each other.

$F= G\frac{m_1m_2}{r^{2} }$

Given,

mass of the sun ( $m_1$ )= $1.99\times10^{23}$ kg

mass of Jupiter( $m_2$ )= $7.79\times10^{8}$ kg

distance between the sun and Jupiter (r)= $1.90\times10^{27}$ m

$F= G\frac{m_1m_2}{r^{2} }\\\\\\F=4.16\times10^{23}\times\frac{1.99\times10^{23}\times7.79\times10^{8}}{({1.90\times10^{27})^2} }$

$F= 4.16\times(10)^{23}$ Newton

Hence the gravitational force between the sun and Jupiter will be $4.16\times10^{23}$

To learn more about gravitational force refer to the link:

brainly.com/question/24783651

4 0

2 years ago