Describe the forces that are acting on a person who is standing still on a sidewalk, and identify whether the forces are balanced or unbalanced. Describe how the forces would change if the person started walking.

Answer:

Energy = 51840 J = 51.84 KJ

Explanation:

The electrical energy delivered to the toy can be found out by the following formula:

[tex]Energy = (Power)(time)\\Energy = (VI)(t)\\Enegry = VIt\\[/tex]

where,

V = Voltage = 3 V

R = Resistance = 2.5 Ω

I = Current = V/R (Ohm's Law) = 3 V/2.5 Ω = 1.2 A

t = time = (4 h)(3600 s/1 h) =  14400 s

Therefore,

[tex]Energy = (3\ V)(1.2\ A)(14400\ s)\\[/tex]

Energy = 51840 J = 51.84 KJ

Answer:

29.39 kg

Explanation:

From the question,

W = mg...................... Equation 1

Where W = weight of the cuboid box, m = mass of the cuboid box, g = acceleration due to gravity.

make m the subject of the equation

m = W/g.................. Equation 2

Given: W = 288 N

Constant: g = 9.8 m/s²

Substitute these values into equation 2

m = 288/9.8

m = 29.39 kg

"This was the idea that non-living objects can give rise to living organisms."

7200 joules of heat and light energy was dissipated into the air. But no work was done ... no force moved through no distance.

Answer:

it depends on the relative masses of the objects.

Explanation:

Answer:

d) 40000 kgm/s

Explanation:

The formula for momentum is p = m*v

so p = 100*400

p = 40000 kgm/s

Answer:

The answer is 1400 J, according to my Physics teacher.

Explanation:

You need to take into account everything that is listed in the question; it's important to remember that the question is asking about the change in gravitational potential energy of the object-object-Earth system from 0s to 10s, not 0s to 20s. :)

Answer:

Freefall

Explanation:

Hi the answer is freefall, hope this helps :)

Answer:

which question

Answer:

The Doppler Effect is given by the following relation;

[tex]f' = \left (\dfrac{v + v_0}{v - v_s} \right) \times f[/tex]

Where;

f' = The frequency the observer hears

f = Actual frequency of the wave

v = The velocity of the sound wave

[tex]v_o[/tex] = The velocity of the observer

[tex]v_s[/tex] = The velocity of the source

Where the observer is stationary, we have;

(i) When the source is moving in the direction of the observer

[tex]f' = \left (\dfrac{v }{v - v_s} \right) \times f[/tex]

(ii) When the source is receding from the observer, we have;

[tex]f' = \left (\dfrac{v }{v + v_s} \right) \times f[/tex]

Therefore;

(a) A person left behind on the platform

For a person left behind on the platform, we have that the radio source is receding, therefore, we have;

[tex]f' = \left (\dfrac{v }{v + v_s} \right) \times f[/tex]

(1) Given that (v + [tex]v_s[/tex]) > v, therefore, v < (v + [tex]v_s[/tex]), f' < f, the frequency heard by the person left on the platform, f', is smaller (lower) than the frequency produced by the radio

(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity

(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively smaller

(b) A person down below floating on a rubber raft

For the the person down below on the rubber raft, the radio source is advancing

Therefore, the radio source is moving towards the person at rest down on the rubber raft, therefore, we have;

[tex]f' = \left (\dfrac{v }{v - v_s} \right) \times f[/tex]

(1) Given that (v - [tex]v_s[/tex]) < v, therefore, f' > f, the frequency heard by the person down below floating on the rubber raft, f', is greater (higher) than the frequency produced by the radio

(2) The frequency is not constant as the speed of the source is increasing while it under the acceleration due to gravity

(3) During the fall, the speed of the source continuously increases under the effect of gravitational attraction and therefore the frequency heard by the person on the platform becomes progressively greater (higher)

Explanation:

Answer:

this is just a guess

Explanation:

a storm spotter only spots the storm and a storm chaser looks for the storm????

Answer:

The 5 Forces

Explanation:

The five forces that influence wind speed and direction are: Pressure gradient force (flow from high to low pressure) Coriolis force (apparent deflecting force due to the rotation of the Earth) Turbulent drag (Earth's surface or objects like trees or grass resist air flow and decrease wind speed near the ground)

Answer:

985 kg/m3

Explanation:

The average density of the human body is 985 kg/m3 k g / m 3 , and the typical density of seawater is about 1020 kg/m3 k g / m 3 .

Explanation:

the worldwide human population density is around 7,500,000,000 ÷ 510,000,000 = 14.7 per km2 (38 per sq. mi.). If only the Earth's land area of 150,000,000 km2 (58,000,000 sq. mi.) is taken into account, then human population density is 50 per km2 (129 per sq.

Answer:

P = 0.0861 W = 86.1 mW

Explanation:

The electrical power in a resistor is defined as the product of the current passing through that resistor and the voltage across that resistor. Therefore, the formula can be written as follows:

[tex]P = VI[/tex]

where,

P = Power in Resistor X = ?

V = Voltage across resistor X =  2.1 V

I = Current passing through resistor X = 0.041 A

Therefore,

[tex]P = (2.1\ V)(0.041\ A)[/tex]

P = 0.0861 W = 86.1 mW

Answer:

The force of friction that the driveway exerts on the ladder ≈ -176.03 N

Please see attached force diagram created with MS Visio

Explanation:

The height of the house painter above the ground = 3.00 m

The length of the ladder = 5.00 m

The height above the ground at which the ladder leans on the wall = 4.70 m

The weight of the painter = 676 N

The weight of the ladder = 107 N

The angle of inclination of the ladder, arcsin(4.7/5) ≈ 70.05°

For equilibrium, the sum of moments at a point, ∑M = 0

Taking moment about point A gives;

4.7 × R = 107 × 2.5 × cos(arcsin(4.7/5)) + 676 × 3.0/(tan(arcsin(4.7/5)))

R = (107 × 2.5 × cos(arcsin(4.7/5)) + 676 × 3.0/(tan(arcsin(4.7/5))))/4.7 ≈ 176.03

The reaction force at the top of the ladder, R ≈ 176.03 N

For equilibrium, we have;

The sum of the horizontal forces, ∑Fₓ = 0

The reaction at the top of the ladder, R + The force of friction that the driveway exerts on the bottom of the ladder, [tex]F_R[/tex] = 0

R + [tex]F_R[/tex] = 0

∴ R = [tex]-F_R[/tex]

R ≈ 176.03 N = [tex]-F_R[/tex]

∴ [tex]F_R[/tex] = -176.03 N

Therefore, the force of friction that the driveway exerts on the bottom of the ladder, [tex]F_R[/tex] ≈ -176.03 N (acting away from the wall).

Answer:

259200

Explanation:

use the formula distance= speed x time

change the 2 hours to seconds (7200) and multiply that number by 36 and it'll give you 259200

Answer:

12 kilometers and hour

Explanation:

Answer:

I think deposition of C is the oldest deposit

Answer:

1. 231.25 mL

2. 218.75 kPa

3. 6.21 L

4. 427.5 mL

5. 83.01 mL

6. 307.6 mL

7. 1.15 L

8. 440.4 mL

Explanation:

This questions describes Boyle's law. Using Boyle's law equation to solve the questions as follows:

P1V1 = P2V2

Where;

P1 = initial pressure

P2 = final pressure

V1 = initial volume

V2 = final volume

Please find the answers to each question as an attachment.

Answer:

A first-class lever: fulcrum is between input and output force; second-class lever: output force is between input force and fulcrum; third-class lever: input force is between fulcrum and output force

Answer:

its "up, then down, then up"

Explanation:

Answer:

hey dream I m your big fan for u I have answered this question The third one is correct.

Answer:

D. Exothermic because energy is a product

Explanation:

ENDOTHERMIC REACTION: A chemical reaction is considered endothermic if the energy is absorbed during the reaction. In other words, if the energy is required by the reactants to proceed with the reaction, then the reaction is endothermic.

EXOTHERMIC REACTION: A chemical reaction is considered exothermic if the energy is released during the reaction. In other words, if the energy is produced as a product of the reaction, then the reaction is exothermic.

Hence, the correct answer for this question will be:

D. Exothermic because energy is a product

Electricity is the [tex]\sf{\underline{flow}}[/tex] of electrons, because electrons [tex]\sf{\underline{passes}}[/tex]  from atom to atom.

Answer:

Final velocity = 7.677 m/s

KE before crash = 202300 J

KE after crash = 182,702.62 J

Explanation:

We are given;

m1 = 1400 kg

m2 = 4700 kg

u1 = 17 m/s

u2 = 0 m/s

Using formula for inelastic collision, we have;

m1•u1 + m2•u2 = (m1 + m2)v

Where v is final velocity after collision.

Plugging in the relevant values;

(1400 × 17) + (4700 × 0) = (1400 + 1700)v

23800 = 3100v

v = 23800/3100

v = 7.677 m/s

Kinetic energy before crash = ½ × 1400 × 17² = 202300 J

Kinetic energy after crash = ½(1400 + 1700) × 7.677² = 182,702.62 J

Answer:

The greater the density of a medium, the slower the speed of sound. This observation is analogous to the fact that the frequency of a simple harmonic motion is inversely proportional to m, the mass of the oscillating object.

Air molecules have more energy at higher temperatures, which means they vibrate faster. This allows the sound waves to also travel faster because they are propelled by collisions between the molecules