A student picks up two spheres that are the same size. One is made of steel and the other is made of aluminum. The student notices that the steel sphere feels much heavier than the aluminum sphere. He then holds one sphere in each hand at eye level and lets go of them at the same time. They fall to the floor. Which ball, if any, will hit the ground first and for what reason

Answer:

P = 24 watts

Explanation:

Given that,

Mass, m = 200 g = 0.2 kg

Velocity of the body, v = 120 m/s

We need to find the power of the body. The formula for power is given by :

P = Fv

Here, F = W (weight) i.e. mg

So,

P = 0.2 × 120

P = 24 Watts

So, the power of the body is 24 watts.

Answer:

M = 0.31 kg

Explanation:

This exercise must be done in parts, let's start by finding the speed of the set arrow plus apple, for this we define a system formed by the arrow and the apple, therefore the forces during the collision are internal and the moment is conserved

let's use m for the mass of the arrow with velocity v₁ = 20.4 m / s and M for the mass of the apple

initial instant. Just before the crash

          p₀ = m v₁ + M 0

instant fianl. Right after the crash

          p_f = (m + M) v

          p₀ = p_f

          m v₁ = (m + M) v

          v =[tex]\frac{m}{m+M} \ v_1[/tex]                          (1)

now we can work the arrow plus apple set when it leaves the child's head with horizontal speed and reaches the floor at x = 8 m. We can use kinematics to find the velocity of the set

          x = v t

          y = y₀ + [tex]v_{oy}[/tex] t - ½ g t²

when it reaches the ground, its height is y = 0 and as it comes out horizontally, [tex]v_{oy} = 0[/tex]

          0 = h - ½ g t²

          t² = 2h / g

For the solution of the exercise, the height of the child must be known, suppose that h = 1 m

            t = [tex]\sqrt{ \frac{ 2 \ 1}{9.8} }[/tex]

            t = 0.452 s

let's find the initial velocity

             v = v / t

             v = 8 / 0.452

             v = 17.7 m / s

From equation 1

              v = m / (m + M) v₁

              m + M = [tex]m \ \frac{v_1}{v}[/tex]

              M = m + m \  \frac{v_1}{v}

we calculate

              M = 0.144 + 0.144  [tex]\frac{20.4}{17.7}[/tex]

              M = 0.31 kg

Answer:

The cyclist with the greatest average speed is Cyclist 4 with average speed of 4.5 m/s

Explanation:

Given;

Cyclist 1 travels 9 m    in    27 s

Cyclist 2 travels 87 m  in    22 s

Cyclist 3 travels 106 m  in   26 s

Cyclist 4 travels 108 m   in   24 s

Determine the average speed of the cyclists as follows;

Average speed of Cyclist 1:    v =  9/27  = 0.33 m/s

Average speed of Cyclist 2:    v = 87/22 = 3.96 m/s

Average speed of Cyclist 3:    v =   106/26 = 4.08 m/s

Average speed of Cyclist 4:     v =   108/24 = 4.5 m/s

Therefore, the cyclist with the greatest average speed is Cyclist 4 with average speed of 4.5 m/s

Answer:

the laws of physics are the same for all non-accelerating observers

Explanation:

Answer:

Mass = 18 kg

Explanation:

Formula for force in centripetal motion is;

F = mv²/r

We have;

Mass; m.

Speed; v = 3 m/s

radius; r = 1.8 m

Force; F = 90 N

Thus;

Making m the subject;

m = Fr/v²

m = 90 × 1.8/3²

m = 18 kg

Answer:

1920Joules

Explanation:

The formula for calculating the kinetic energy of a body is expressed as;

KE = 1/2 mv²

m isthe mass

V is the speed

For the two masses, the combined KE is expressed as;

KE  = 1/2(m1+m2)v²

KE = 1/2(45+15)(8)²

KE  = 1/2 * 60 * 64

KE  = 30 * 64

KE  = 1920J

Hence the combined kinetic energy of the boy and the bicycle is 1920Joules

The combined kinetic energy of the boy and the bicycle is of 1920 J.

Given data:

The mass of boy is, m = 45.0 kg.

The mass of bicycle is, M = 15.0 kg.

The speed of bicycle is, v = 8.00 m/s.

The kinetic energy of an object is defined as the energy possessed by an object by virtue of motion of object. The combined kinetic energy of the boy-bicycle system is given as,

[tex]KE = \dfrac{1}{2}(m+M)v^{2}[/tex]

Solve by substituting the values as,

[tex]KE = \dfrac{1}{2}(45+15) \times 8^{2}\\\\KE = 1920 \;\rm J[/tex]

Thus, we can conclude that the combined kinetic energy of the boy and the bicycle is of 1920 J.

Learn more about the concept of kinetic energy here:

https://brainly.com/question/12669551

Answer:

Aluminum and steel are good conductors of electricity.

Explanation:

1) All materials are good conductors of electricity.

This is false because nonmetal materials such as plastic or wood cannot conduct electricity.

2) Aluminum and steel are good conductors of electricity.

This is true. All metals are conductors of electricity.

3) Gold and wood are poor conductors of electricity.

This is false. Although gold can conduct electricity, wood can't.

4) Plastic and copper are good conductors of electricity.

This is false. Although copper can conduct electricity, plastic can't.

I hope this helps!

Answer:

B) Aluminum and steel are good conductors

Explanation:

Answer:

Explanation:

because it is godhood

Answer:

Explanation:

Intensity of light is inversely proportional to distance from source

I ∝ 1 /r²  where I is intensity and r is distance from source . If I₁ and I₂ be intensity at distance r₁ and r₂ .

I₁ /I₂ = r₂² /r₁²

If r₂ = 4r₁ ( given )

I₁ / I₂ = (4r₁ )² / r₁²

= 16 r₁² / r₁²

I₁ / I₂ = 16

I₂ = I₁ / 16

So intensity will become 16 times less bright .

"16 times " is the answer .

Answer:

(C) because the elevator is not accelerating

Note  F = M a = M g (the resultant force on the elevator is due to gravity)

or  Fup = Fc   the force exerted on the elevator by the cable

and Fdown = Fe    the force exerted on the elevator by gravity

F = M a = Fup - Fdown = zero    resultant force on elevator

I think the answer would be A.

After all, it is 0 which is technically a dead center number meaning that the net should be balanced and still.

Hope this helps and have a nice day.

-R3TR0 Z3R0

Answer:

 A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave. I hope I got it correct !!

Answer:

Current in a parallel circuit = 0.61 amps (Approx)

Explanation:

Given:

Voltage V = 6 volt

Two resistors = 17.2 , 22.4 in parallel circuit

Find:

Current in a parallel circuit

Computation:

1/R = 1/r1 + 1 / r2

1/R = 1/17.2 + 1 / 22.4

R = 9.73 ohms (Approx)

Current in a parallel circuit = V / R

Current in a parallel circuit = 6 / 9.73

Current in a parallel circuit = 0.61 amps (Approx)

Explanation:

angular velocity = velocity/radius

= 5/2

= 2.5 rad/s

Answer:

Dakota moves a magnetic toy train toward a magnet that cannot move. What happens to the potential energy in the system of magnets during the movement? The potential energy increases because the train moves against the magnetic force. The potential energy decreases because the train moves against the magnetic force.

I hope this helps you :)

Answer: See explanation

Explanation:

From the information given in the question, the journal entry is written below:

Debit: Merchandise inventory 1960

Credit: Account payable 1960

(To record purchase)

Note that 1960 was gotten as:

= 2000 × 98%

= 2000 × 0.98

= 1960

Note that 2% discount was given.

Answer:

 ΔV = -2.1 L

Explanation:

To solve this exercise we can use the ideal gas equation for two points

         PV = nRT

          P₁V₁ = P₂ V₂

where point 1 is on the surface and point 2 is at the desired depth,

          V₂ = [tex]\frac{P_1}{P_2} \ V_1[/tex]

let's calculate

           V₂ = ( [tex]\frac{1 atm}{2.5 atm}[/tex] ) 3.5 L

            V₂ = 1.4 L

this is the new volume, the change in volume is

          ΔV = V₂ -V₁

          ΔV = 1.4-3.5

          ΔV = -2.1 L

Answer:

1.6 Hz

Explanation:

In simple harmonic motion, acceleration is given by the formula;

a = Aω²

Where;

A is amplitude

ω is angular velocity.

We are given A = 9.7 cm = 0.097 m

We know that acceleration due to gravity is 9.8 m/s².

Thus;

9.8 = 0.097ω²

ω² = 9.8/0.097

ω = √101.031

ω = 10.05 rad/s

Formula for frequency is;

f = ω/2π

Thus;

f = 10.05/2π

f = 1.6 Hz

Answer:

The correct answer is:

(a) 0

(b) 0.5 m/s

(c) 7740 N

(d) 0

Explanation:

The given values are:

mass,

m = 3000 kg

Tension,

T = 7,200 N

Angle,

= 30°

(a)

Even as the block speed becomes unchanged, the kinetic energy (KE) will adjust as well:

⇒ [tex]\Delta K =0[/tex]

By using the theorem of energy, the net work done will be:

⇒  [tex]\Delta K =0[/tex]

(b)

According to the question, After 0.25 m the block is moving with the constant speed

= 0.5 m/s.

(c)

The given kinetic friction coefficient is:

u = 0.3

The friction force will be:

= [tex]u(mg-Tsin30^{\circ})[/tex]  

On substituting the values, we get,

= [tex]0.3[(3000\times 9.8)-(7200\times 0.5)][/tex]

= [tex]0.3[29400-3600][/tex]

= [tex]0.3\times 25800[/tex]

= [tex]7,740 \ N[/tex]

(d)

On including the friction,

The net work will be:

⇒ [tex]\Delta K=0[/tex]

Answer:

An object which experiences either a change in the magnitude or the direction of the velocity vector can be said to be accelerating. This explains why an object moving in a circle at constant speed can be said to accelerate - the direction of the velocity changes.

if a car turns a corner at constant speed, it is accelerating because its direction is changing. The quicker you turn, the greater the acceleration. So there is an acceleration when velocity changes either in magnitude (an increase or decrease in speed) or in direction, or both.

Explanation:

Answer:

something that can be burned to produce heat

Explanation:

Combustion can be defined as an exothermic chemical reaction between physical substances, usually in the presence of oxygen and hydrocarbons to produce heat, light and carbon.

A fuel can be defined as something that can be burned to produce heat.

In the process of heat conduction, thermal energy is usually transferred from fast moving particles to slow moving particles during the collision of these particles. Also, thermal energy is typically transferred between objects that has different degrees of temperature and materials (particles) that are directly in contact with each other but differ in their ability to accept or give up electrons.

Answer:

* roller skates and ice skates.

* roller coaster

Explanation:

One of the best examples for this situation is when we are skating, in the initial part we must create work with a force, it compensates to move, after this the external force stops working and we continue movements with kinetic energy, if there are some ramps, we can going up, where the kinetic energy is transformed into potential energy and when going down again it is transformed into kinetic energy. This is true for both roller skates and ice skates.

Another example is the roller coaster, in this case the motor creates work to increase the energy of the car by raising it, when it reaches the top the motor is disconnected, and all the movement is carried out with changes in kinetic and potential energy. In the upper part the energy is almost all potential, it only has the kinetic energy necessary to continue the movement and in the lower part it is all kinetic; At the end of the tour, the brakes are applied that bring about the non-conservative forces that decrease the mechanical energy, transforming it into heat.

Answer:

Absorbed sunlight is balanced by heat radiated from Earth's surface and atmosphere. ... The atmosphere radiates heat equivalent to 59 percent of incoming sunlight; the surface radiates only 12 percent. In other words, most solar heating happens at the surface, while most radiative cooling happens in the atmosphere

Answer:

Explanation:

Hope this helps!

Answer:

The side of the paper with sunblock lotion stays on its the same color/tone while the other side of the paper without sunblock lotion faded

Explanation:

Ultraviolet (UV) radiation from the sun is the main cause of skin cancer, so one of the best ways to prevent skin cancer is to protect your skin from sun exposure with the use of sunscreen/sunblock. The sunlight that reaches us is made up of two types of harmful rays: long waves (UVA) and short waves (UVB)

Answer:

Explanation:

Range R = 7 m

angle of projection θ = 40⁰

u² sin2θ / g = R where u is velocity of throw.

u² sin 80 / g = 7

u² = 69.71

u = 8.35 m/s

horizontal velocity = u cos 40 = 8.35 cos 40

= 6.4 m /s

vertical velocity = u sin 40 = 8.35 sin40

= 5.37 m /s

Maximum height :-

v² = u² - 2gh , u is initial vertical component of throw.

0 = 5.37² - 2 x 9.8 x h

h = 1.47 m

Time to reach max height :--

v = u - gt

o = 5.37 - 9.8 t

t = .55 s

Answer:

I only know number 4 is correct

Explanation:

2 people

Explanation:

Answer:

dude the answer is upright