A 0.50 kilogram ball is held at a height of 20 meters. What is the kinetic energy of the ball when it reaches halfway after being released?
A.
49 joules
B.
98 joules
C.
1.0 × 102 joules
D.
1.1 × 102 joules

Answer:

2,450

400

Explanation:

Pls brainliest me

Answer:

51 miles/hour

Explanation:

Talia is on a road trip with some friends. in the first 2 hours, they travel 100 miles. then they hit traffic and go only 30 miles in the next hour. the last hour of their trip, they drive 75 miles. calculate the average speed of talia’s car during the trip. give your answer to the nearest whole number.

The average speed would be 51 miles/hour.

The average speed of a moving object is defined as the total distance traveled relative to the total time taken fro the journey. Mathematically, it is given as:

  total distance traveled/total time taken.

In this case;

Total distance traveled = 100 + 30 + 75 = 205 miles

Total time taken = 2 + 1 + 1 = 4 hours

Therefore;

Average speed = 205/4 = 51.25 miles/hour

To the nearest whole number = 51 miles/hour

Explanation:

in the first thing we are allowing bacteria to grow

in the second one we are killing it

Answer:

v = 0.3 ms⁻¹

Frequency = 4.8 Hz

T = 0.21 sec

Explanation:

The rate of oscillation is 4.8 oscillation/second

Let's see frequency's definition " no. of vibration/oscillation per unit time"

So,

Frequency = 4.8 Hz

Now

Time period is the reciprocal of frequency

T = 1/f

T = 1/4.8

T = 0.21 sec

Now

Using formula

v = f λ

f = 4.8 Hz , λ = 6 cm (But we need to convert it in a standard form)

So, λ = 0.06 m

Putting in formula

v = (4.8)(0.06)

v = 0.3 ms⁻¹

Answer:

(a) The package lands 682 meters horizontally ahead from the point the package was dropped from the plane

(b) The horizontal component = 39.0 m/s

The vertical component = 171.55 m/s

(c) The angle of impact is 77.19°

Explanation:

The parameters given are;

Velocity of the plane, vₓ = 39.0 m/s

Height of the plane above the ground, h = 1.50 × 10² m = 1,500 m

(a) The time, t, before the package hits the ground when dropped from the plane is given by the relation;

h = u·t + 1/2×g×t²

Where:

g = Acceleration due to gravity = 9.81 m/s²

u = Initial vertical velocity = 0 m/s

Hence;

1500 = 0×t + 1/2 × 9.81 × t² = 4.905·t²

∴ t = √(1500/4.905) = 17.49 s

The horizontal distance the package travels before landing = 17.49 × 39 ≈ 682 m

The package lands 682 meters horizontally ahead from the point the package was dropped from the plane

(b) The vertical velocity, [tex]v_y[/tex], of the package just before landing is given by the relation;

[tex]v_y[/tex]² = u² + 2·g·h

u = 0 m/s

∴ [tex]v_y[/tex]² = 0 + 2×9.81×1500 = 29430 m²/s²

[tex]v_y[/tex] = √29430  = 171.55 m/s

Hence the horizontal component = 39.0 m/s

The vertical component = 171.55 m/s

(c) The angle of impact, θ, is given as follows;

[tex]tan \theta = \dfrac{v_y}{v_x} = \dfrac{171.55}{39.0 } = 4.4[/tex]

∴ θ = tan⁻¹(4.4) = 77.19°.

Answer: Find the answer in the explanation

Explanation:

The music playing on the radio will be heard through the sound waves coming from the radio.

The travelling wave will obey Newton's first law of motion which state that:

An object or particle will remain at rest or continue its linear motion in a straight line except an external force is applied.

The external force through wind could affect the travelling of the sound waves. Since the wave is longitudinal wave. That is, it needs a medium (air) for its propagation.

Answer:

ok

Explanation:

Ok

Answer:

F = 37.5 N

Explanation:

It is given that,

Mass of the object is 5 kg

Acceleration of the object is 7.5 m/s²

We need to find the force experienced by the object. The force is given by the product of mass and acceleration of an object. So,

F = m

[tex]F=5\times 7.5\\\\F=37.5\ N[/tex]

So, the force acting on the object is 37.5 N.    

Answer:Ghana - Accra Togo - Lomé I hope this helps mark me brainlist

Explanation:

Accra is the Capital of Ghana

Accra was founded in the 17th century by the Ga people. It became the capital of the British Gold Coast in 1877 and the capital of Ghana on the formation of the country as an independent state in 1957
Accra Is the Second Most Expensive City in Africa

Accra is known for its colorful textile and used or second-hand clothing markets. Located inside the Makola Market, Kantamanto is the largest trading point in all of Accra.

The capital of Togo is Lomé

Lomé, city, capital of Togo. Lomé lies on the Gulf of Guinea (Atlantic coast) in the extreme southwestern corner of the country. Selected as the colonial capital of German Togoland in 1897, it became important as an administrative, commercial, and transport centre.

It is also the country's chief port, from where it exports coffee, cocoa, copra, and oil palm kernels- Lome

Lomé was founded by the Ewe, an indigenous ethnic group, in 1880. Located on the southwestern Atlantic coast of Togo, Lomé has a long history of trade. In 2000, an estimated 900,000 people resided in Lomé. Europe's “Scramble for Africa” began in 1880.

Answer:

During charging by conduction, both objects acquire the same type of charge. If a negative object is used to charge a neutral object, then both objects become charged negatively. ... In this case, electrons are transferred from the neutral object to the positively charged rod and the sphere becomes charged positively.

Answer:

[tex]R_s = 0.093 \Omega[/tex]

Explanation:

Voltage of the car battery = 12.0 V

Voltage drop in the battery = 3.4 V

The remainder of the voltage is the starter voltage, that is:

Starter voltage = Initial battery voltage - voltage drop

Starter voltage = 12.0 - 3.4

Starter voltage, [tex]V_{s}[/tex] = 8.6 V

Current drawn by starter, [tex]I_s[/tex] = 93 A

According to Ohm's law: [tex]V_s = I_s R_s[/tex]

Starter Resistance, [tex]R_s[/tex] = [tex]V_s/I_s[/tex]

[tex]R_s = 8.6/93\\R_s = 0.093 \Omega[/tex]

Answer:

7.61 m/s

Explanation:

Given:

Δx = 87.4 m

v = 21.0 m/s

t = 6.11 s

Find: v₀

Δx = ½ (v + v₀) t

87.4 m = ½ (21.0 m/s + v₀) (6.11 s)

v₀ = 7.61 m/s

71.6

Δx = 87.4 m

v = 21.0 m/s

t = 6.11 s

Find: v₀

Δx = ½ (v + v₀) t

87.4 m = ½ (21.0 m/s + v₀) (6.11 s)

v₀ = 7.61 m/s

Answer: 0.326kg

Explanation:

Given the following :

Mass of copper (Mc) = 253g

Initial temperature of copper (t1) = 85°C

Mass of aluminium(Ma)=?

Initial temperature of aluminum(t1) = 5°C

Specific heat capacity of aluminum(Ca) = 900

Specific heat capacity of copper (Cc) = 387

Final temperature(t2) = 5°C

Q = mc(t2 - t1)

Ma × Ca × (t2 - t1)a = Mc × Cc × (t2 - t1)c

Ma × 900 × (25 - 5) = 0.253 × 387 × (25 - 85)

Ma × 900 × 20 = 0.253 × 387 × 60

Ma × 18000 = 5874.66

Ma = 5874.66 / 18000

Ma = 0.32637

Ma = 0.326kg

The mass of the aluminum chunk dropped into the water is 325.5 g.

The given parameters;

Apply the principle of conservation of energy, the heat gained by the aluminum is equal to heat lost by the copper;

[tex]M_a C_a (t- t_a) = M_c C_c (t_c - t)\\\\M_a\times 0.9 \times (25-5) = 253 \times 0.386 \times (85-25)\\\\18 M_a = 5859.48\\\\M_a = \frac{5859.48}{18} \\\\M_a = 325 .5 \ g[/tex]

Thus, the mass of the aluminum chunk dropped into the water is 325.5 g.

Learn more here: https://brainly.com/question/20709851

Answer:  Force per unit area. Explanation: P = 25/20. P = 5/4 Pascal or 1.25 Pascal

Explanation: is this what you were looking for

The available options are:

A. bartenders serving alcohol

B. students identifying their professors.

C. Doctors diagnosing cases of schizophrenia.

D. eyewitnesses identifying suspects from a lineup.

Answer:

A.  bartenders serving alcohol

Explanation:

This is because of the underage rule concerning sale of alcohol. Thus, there are occasional period in which underage person or a minor will want to buy alcohol, and without necessarily asking for the birth certificate or ID card that contains Age information, it is therefore, necessary for bartenders to be able to tell the age of their unfamiliar customers, by mere looking at them, so as not to sell to a minor.

Hemce, Rhodes research in guessing the age of unfamiliar person has important implications for BARTENDERS SERVING ALCOHOL, because it will guide them to determine Underage or Minor, that want to buy alcohol from them.

Answer:

Explanation:

the diagonal of the rectangular plot of land  can be found using Pythagoras theorem (the diagonal is the hypotenuse)

Given

length of land x= 48m

width of land y= 20m

digonal z= ?

[tex]z^2= x^2+y^2\\\\z=\sqrt{ x^2+y^2} \\[/tex]

substituting the values of x and y into the equation we can solve for z

[tex]z=\sqrt{ 48^2+20^2} \\\\z=\sqrt{ 2304+400} \\z=\sqrt{ 2704} \\z=52m\\[/tex]

The diagonal is 52m

Hence since the interval = 22m the number if treee is

[tex]\frac{52}{22} = 2.36\\[/tex]

The number of trees must be whole numbers , the number of tree is 2

Answer:

The force acting on it is lift

Explanation:

they would formulate a new hypothesis with the same dependent variable but a different independent variable as a virginal hypothesis .

A cord is wrapped around the outer surface of the 8-kg disk. If a force of F = (1⁄4θ²) N, where θ is in radians, is applied to the cord, determine the disk’s angular acceleration when it has turned 5 revolutions. The disc has an initial angular velocity [tex]\omega _o = 1 \ rad/s[/tex] and radius from the center of the disc = 300 mm

Answer:

the angular acceleration = 205.706 rad/sec²

Explanation:

GIVEN THAT:

The disc mass = 8 kg

Force = [tex]\dfrac{1}{4} \ \ \theta ^2* N[/tex]

We are told that the given θ is in radians; Therefore; the when it has turned 5 revolutions; we have the θ to be:

[tex]\theta = 5 rev * (\dfrac{2 \ \pi * rad}{1 rev}) \\ \\ \theta = 10 \ \pi \ rad[/tex]

Also;

the initial angular velocity [tex]\omega _o = 1 \ rad/s[/tex]

radius from the center of the disc = 300 mm = 0.3 m

Thus; the mass moment about the Inertia can be determined via the following expression;

[tex]I_o = \dfrac{1}{2}*m*r^2[/tex]

[tex]I_o = \dfrac{1}{2}*8*0.3^2[/tex]

[tex]I_o = 0.36 \ kg/m^3[/tex]

Now to calculate the angular acceleration; we equate the sum of the moments acting on the Inertia;

SO:

[tex]\sum M_o = I_o \alpha[/tex]

[tex]F*0.3 = 0.36* \alpha[/tex]

[tex]\dfrac{1}{2}* \theta^2 *0.3 = 0.36* \alpha[/tex]

[tex]\alpha = 0.20836 \ \theta^2 \ rad/sec^2[/tex]

[tex]\alpha = 0.20836 \ (10 \ \pi )^2 \ rad/sec^2[/tex]

[tex]\alpha = 205.706 \ rad/sec^2[/tex]

Hence; the angular acceleration = 205.706 rad/sec²

Answer:

1.5m/s2

Explanation:

F=ma

a=F/m

a=15/10

a=1.5m/s2

Answer:

0.333

Explanation:

Weight of the sinker in water = 25gf

Weight of cork in air and sinker in water = 25gf + 2.5gf

= 27.5gf

Weight of the cork and sinker in water = 20gf

Loss of weight of cork in water = 27.5- 20 = 7.5gf

Rd of cork = weight of cork in air/ loss of weight of cork in water

= 2.5/7.5

= 1/3

= 0.333

Hence the Relative density of the cork is 0.333

Answer:

The correct order of answers goes:

[tex]\left[\begin{array}{ccc}Ionic\\Electronegativity\\Metallic\\Cation\end{array}\right][/tex]

Explanation:

Ionic - Ionic bonds are formed between a metal and a nonmetal (typically). Nonmetals are typically more electronegative elements because they are seeking to gain electrons to achieve atomic stability while metals want to give up electrons to those elements to become atomically stable. Therefore, the nonmetals are much more electronegative in comparison to the metals.

Electronegativity - Electronegativity is used mathematically to predict the type of bond that will occur between elements. The larger electronegativity has the smaller electronegativity subtracted from it to give us a number that we then apply to ranges within a table and try to decipher what kind of bond will be formed.

Metallic - This plays into both explanations already given. Metallic bonds will form between metals, meaning their electronegativities will be much lower. Higher differences between electronegativities (anything above 1.7) is considered ionic, while anything from 0.1 to 1.69 is considered covalent (these split to make polar and nonpolar covalence).

Cation - Cation is the term for a positively charged ion. It comes from cathode (a scientist completed an experiment with the cathode ray tube where they accelerated positively charged particles throughout it).

The boat has to pull with MORE force. Don't forget about the force of friction with the water, pulling the skier in the backwards direction. The force that accelerates him is the NET force ... boat force minus water resistance. So the boat force has to be greater than the net accelerating force.

Answer:

m = 1,975 m / kg , b = 38.05 m

Explanation:

In this experiment, the elongation is plotted against the applied mass

getting a straight line

            y = m x + b

where b would be the initial length of spring let's calculate the slope for which we use two well separated points

           m = (56.3 -48.4) / (8 - 4)

           m = 1,975 m / kg

the equation remains

         y = 1,975 x + b

for x = 2 kg y = 42.0 m

we substitute in the equation

           42 = 1,975 2 + b

           b = 42 - 3.95

           b = 38.05 m

Answer:

D

Explanation:

Now we know that Force is the rate of change of momentum meaning

F= mv/t

But

mv/t = Ke

v/t = ke/m

a= ke/m

Where a is acceleration

K is constant of proportionality of tension on a spring

e is the extension substended by a string.

From the formula of acceleration we can see that as mass decreases acceleration increases so we can see that m = 1

We would have a maximum value of acceleration.

The Answer Is....:

D.

Answer:

2.331

Explanation:

It just the change of Energy from potential (PE) to kinetic (KE)

PE on A = PE on B + KE on B + friction works (Wf)

mg(ha) = mg(hb) + ½mv² + Wf

35 * 9.8 * 1.5 = 35 * 9.8 * 0.8 + ½ * 35 * v² + 145

514.5 = 274.4 + 17.5v² + 145

514.5 - 274.4 - 145 = 17.5v²

17v² = 95.1

v² = 5.434

v =√5.434 = 2.331 m/s

Answer:

a_max = 50 cm/s^2

Explanation:

To find the magnitude of the maximum acceleration of the particle, you take into account the equation of motion in a simple harmonic motion:

[tex]x=Acos(\omega t)[/tex]

ω: angular velocity = 10 rad/s

A: amplitude = 5 cm

The acceleration is given by:

[tex]a=\omega^2 x[/tex]

and the maximum acceleration is obtained when the cosine function is maximum, that is, when cos(wt) = 1. Then, you have:

[tex]a_{max}=\omega^2 x_{max}=\omega^2A[/tex]

Then, you replace the values of w and A in order to calculate a_max:

[tex]a_{max}=(10rad/s)^2(5cm)=50\frac{cm}{s^2}[/tex]

hence, the maximum acceleration is 50 cm/s^2

Answer:

Explanation:

so, p1v1=p2v2

p2=p1xv1/v2

Answer:

9.45 kWh

Explanation:

Energy = Power × time

E = 900 W × (1.5 h/day × 7 day)

E = 9450 Wh

E = 9.45 kWh