What does it mean when work is positive?

Answers

Answer 1
Both positive work and negative work have meaning: Positive work follows when the force has a component parallel to the displacement. Positive work adds energy to a system. Negative work follows when the force has a component opposite or against the displacement.

Related Questions

can someone pls help me with this?

Answers

C because they are both going in a constant speed

Reena has rolled down her toy car through a ramp. When she increases the height of the ramp (10 cm ) the car has travelled 5 metres and she increases the height of the ramp (13 cm) the car has travelled 6 metres . What happened when she raises the height of the ramp?

Answers

Answer:

As she raises the height of the ramp, the speed of the toy car decreases.

Explanation:

Speed is the ratio of the distance traveled by an object to the time taken.

i.e speed = [tex]\frac{distance}{time}[/tex]

From the given question, it would be observed that:

i. when the height of the ramp was 10 cm, the car traveled 5 meters.

ii. when the height of the ramp was increased to 13 cm, the car traveled 6 meters.

Therefore, an increase in the height of the ramp causes a decrease in the speed of the toy car so that the distance traveled per unit time increases. Showing that there is an inverse relationship between the height of the ramp and the speed of the toy car.

Which device consists of two separate coils of wire wrapped around an iron
ring?
O A. A transformer
B. A generator
C. A motor
D. A commutator

Answers

Answer:

It would be transformer

Explanation:

hope this helped

Answer:

transformer

Explanation:

got it right

4. A box of books weighing 325 N moves at a constant velocity across the floor when the box is pushed with a force of 425 N exerted downward at an angle of 35.2° below the horizontal. Find mk between the box and the floor.

Answers

Answer:

0.61°

Explanation:

Since the box move at constant velocity, it means there is no acceleration then we can say it has a balanced force system.

Pulling force= resistance force

From the formula for pulling force,

F(x)= Fcos(θ)

= 425×cos(35.2)

=347N

The force exerted downward at an angle of 35.2° below the horizontal= Fsin(θ)= 425sin(35.2)

=425×0.567=245N

Resistance force= (325N+ 245N) (α)= 570N(α)

We can now equates the pulling force to resistance force

570 (α)= 347N

(α)= 347/570

= 0.61

kinetic energy is energy in the form of motin

Answers

Answer:

yes

Explanation:

is it true that scientific theories and scientific laws both describe observed events??? provide evidence!!!!! only 2 people could answer so if you can't then comment and provide evidence thank you very much!!!!!!

Answers

Answer:

I'm not positive but I think the answer is Yes, because both scientific laws and theories are based on evidence.

Explanation:

Sorry I don't have notes on this, hope this helps! :)

To get to the kitchen from her bedroom, Maria walks 3 m north and then 4
m east. What is the total distance and displacement of Maria? *

Answers

Distance = 3+4 = 7m
Displacement = Use Pythagoras theorem to get, square root 3^2 + square root 4^2 = 3 + 2 = 5 meters

The components of a 15-meters-per-second velocity at an angle of 60.° above the horizontal are (1) 7.5 m/s vertical and 13 m/s horizontal (2) 13 m/s vertical and 7.5 m/s horizontal (3) 6.0 m/s vertical and 9.0 m/s horizontal (4) 9.0 m/s vertical and 6.0 m/s horizontal

Answers

Answer:

13 m/s vertical and 7.5 m/s horizontal

Explanation:

❤️

The vertical and horizontal components of a projectile is required.

The correct option is (2) 13 m/s vertical and 7.5 m/s horizontal

u = Initial velocity of projectile = 15 m/s

[tex]\theta[/tex] = Angle of projectile = [tex]60^{\circ}[/tex]

The horizontal component

[tex]u_x=u\cos \theta\\\Rightarrow u_x=15\cos60^{\circ}\\\Rightarrow u_x=7.5\ \text{m/s}[/tex]

The vertical component

[tex]u_y=u\sin \theta\\\Rightarrow u_x=15\sin60^{\circ}\\\Rightarrow u_x=13\ \text{m/s}[/tex]

Learn more:

https://brainly.com/question/24681896

https://brainly.com/question/2686378

________ is the speed and direction of an object

Answers

Answer:

velocity

Explanation:

plz mark brainliestʕ•ᴥ•ʔ

Velocity is the answer

A car accelerates uniformly from rest to a final speed of 19 m/s in 10. seconds. How far does it travel during this period of acceleration?

Answers

Answer:

x = 95 [m]

Explanation:

To solve this problem we must use the following equation of kinematics.

[tex]v_{f} =v_{o} +a*t[/tex]

where:

Vf = final velocity = 19 [m/s]

Vo = initial velocity = 0 (starts from the rest)

a = acceleration [m/s²]

t = time = 10 [s]

Now we can find the acceleration

19 = 0 *a*(10)

a = 1.9 [m/s]

With the second equation we can find the distance:

[tex]v_{f} ^{2} =v_{o} ^{2} +(2*a*x)[/tex]

where:

x = distance [m]

(19)² = (0)² + (2*1.9*x)

3.8*x = 361

x = 95 [m]

two monkeys were swinging on vines together. One monkey got stuck hanging from a branch unable to move. the other monkey, who was very smart,knew that to move he needed to have a net force in the direction he wanted to go

Answers

Answer:

Hi, what is the question here?

Explanation:

Happy to help if I'm able to

29. Identify whether each of the following is a form of mechanical energy:
elastic potential energy, chemical potential energy, gravitational potential
energy.

Answers

Explanation:

elastic potential energy, chemical potential energy, and gravitational potential energy are all forms of mechanical energy.

Mechanical energy includes elastic potential energy, chemical potential energy, and gravitational potential energy.

What is Mechanical energy?Mechanical energy is the energy that an object has as a result of its motion or position. Because it is stretched out in that position, a pulled bow has mechanical energy (elastic potential energy). Chemical potential energy is the energy that a substance has stored in its chemical bonds. A barbell hoisted high above a weightlifter's head has mechanical energy because of its vertical position above the ground (gravitational potential energy).The sum of kinetic and potential energy in an object used to perform a specific task is known as mechanical energy. In other words, it describes the energy of an object as a result of its motion, position, or both.

To learn more about mechanical energy, refer

https://brainly.com/question/19130644

#SPJ2

What is the speed in kilometers per hour of a 27.78m/s baseball pitch?

Answers

Answer:

100.008 km/h

Explanation:

multiply the speed value by 3.6


A cannon sitting on the edge of a cliff 500 meters above the ground shoots a cannon ball with a horizontal velocity of 100m/s. At some point the cannon hits the ground. How far away from the point it was launched will the cannon ball land?​

Answers

Answer:

1010 m

Explanation:

The following data were obtained from the question:

Height (h) of cliff = 500 m

Horizontal velocity (u) = 100 m/s

Horizontal distance (s) =?

Next we shall determine the time taken for the cannon ball to hit the ground. This can be obtained as follow:

Height (h) of cliff = 500 m

Acceleration due to gravity (g) = 9.8 m/s²

Time (t) =?

h = ½gt²

500 = ½ × 9.8 × t²

500 = 4.9 × t²

Divide both side by 4.9

t² = 500/4.9

Take the square root of both side

t = √(500/4.9)

t = 10.1 s

Finally, we shall determine the horizontal distance travelled by the cannon ball.

This can be obtained by using the following formula (s = ut) as illustrated below:

Horizontal velocity (u) = 100 m/s

Time (t) = 10.1 s

Horizontal distance (s) =?

s = ut

s = 100 × 10.1

s = 1010 m

Thus, the cannon ball was launched 1010 m away from the cliff.

What happens to the minerals as gneiss forms from schist?

Answers

Answer:

Explanation:

Gneiss is a high grade metamorphic rock, meaning that it has been subjected to higher temperatures and pressures than schist. However, unlike slate and schist, gneiss does not preferentially break along planes of foliation because less than 50% of the minerals formed during the metamorphism are aligned in thin layers.

When using a liquid as a solvent, what could be the state(s) of matter of the solute?

Answers

Answer:

Explanation:

it can be a gas like carbon dioxide in soda

it can be liquid like alcohol in water

it can be solid like sugar and salt

Answer

✔ all three states

Explanation:

TOOK THE TEST

What is the mass of an object on the moon whose weight sitting on the Earth is 1900 N?

Answers

Fg=mg
Fg/g=m
m=(1900N) / (9.81N/kg)
m=193.68kg

HELP! NEED THE ANSWER IN 6 MINS!!!!!!!!!!!!!!!

Answers

Answer:

C

Explanation:

Bird man is flying horizontally at a speed of 33m/s and a height of 86m. Bird man releases a turd directly above the start of the field. How far from the start of the field should the robot hold the bucket to catch the turd.

Answers

Answer:

2838

Explanation:

A car initially traveling at 25 m/s speeds up to 60 m/s under a uniform acceleration of 5.0 m/s2 to avoid being hit by another car. How long does it take the car to speed up and get out of the way? Show your work.

Answers

Answer:

The car takes 7 seconds to speed up and get out of the way

Explanation:

Constant Acceleration Motion

It's a type of motion in which the velocity of an object changes uniformly over time.

Having a as the constant acceleration, vo the initial speed, vf the final speed, and t the time, the following relation applies:

v_f=v_o+at

Using the above equation we can solve for t:

[tex]\displaystyle t=\frac{v_f-v_o}{a}[/tex]

The car has an initial speed of vo=25 m/s and ends up at vf=60 m/s with an acceleration of a=5 [tex]m/s^2[/tex].

Given all the appropriate data, calculate t:

[tex]\displaystyle t=\frac{60-25}{5}[/tex]

Calculating:

[tex]\displaystyle t=\frac{35}{5}[/tex]

t = 7 seconds

The car takes 7 seconds to speed up and get out of the way

Question 2 of 10
Which of the following careers would physicists be least qualified to perform,
based on their training?
A. Nuclear engineer
B. Solar panel designer
C. Research lab manager
D. Gardener

Answers

Answer:

a and d

Explanation:

a because a nuclear engineer is more on explosions which links to chemistry and d because Gardner is irrelevant

d is the right one bc it’s gardening

A 10 V fan with a current of 2 A is turned on for 30 seconds. Calculate the energy transferred in joules,

Answers

Answer:

E = 600 J

Explanation:

Given that,

Voltage, V = 10 V

Current, I = 2 A

Time, t = 30 s

We need to find the energy transferred. Energy transferred is calculated as follows :

[tex]E=I^2Rt[/tex]

Ohm's law, V = IR, R = V/I

[tex]E=I^2\times \dfrac{V}{I}\times t\\\\E=IVt\\\\E=2\times 10\times 30\\\\E=600\ J[/tex]

So, 600 J of energy is transferred.

Answer:600J

Explanation:

A juggler throws a beanbag into the air with a speed of 1.0 m/s.

How long does it take for the beanbag to reach its maximum height?

Answers

i got a 46 on that test

An archer stands on the ground and fires an arrow at a target. A second archer stands at the top of a building and holds an arrow in his hand. Which arrow has more potential energy?
In the same scenario described in question 7, which arrow has more kinetic energy? Explain.

Answers

Answer:

The arrow of the second archer standing on a high building will have more potential energy.

The arrow of the first archer standing on ground will have more kinetic energy.

Explanation:

POTENTIAL ENERGY:

The potential energy of an object depends upon its height, as given in the formula:

P.E = mgh

Hence, the arrow with the greater height will have more potential energy.

Therefore, the arrow of the second archer standing on a high building will have more potential energy.

KINETIC ENERGY:

The kinetic energy of an object depends upon its speed, as given in the formula:

K.E = (1/2)mv²

Hence, the arrow with the greater speed will have more kinetic energy energy. Since, the second arrow is stationary, it will have zero kinetic energy. But, the first arrow will have some K.E due to its speed.

Therefore, the arrow of the first archer standing on ground will have more kinetic energy.

(a)  The second archer standing at the top of the building will have more potential energy.

(b) The first archer on the ground level will have the more kinetic energy.

The potential energy of an object is the energy possessed by the object by virtue its position above above the ground.

P.E = mgh

where;

h is the height above the ground

Thus, the second archer standing at the top of the building will have more potential energy.

(b) The kinetic energy of an object is the energy possessed by the object due to its motion.

K.E = ¹/₂mv²

where;

v is the speed of the object

An object in motion, has zero velocity at maximum height but maximum velocity on the ground level.

Thus, the first archer on the ground level will have the more kinetic energy.

Learn more here:https://brainly.com/question/21866017

A 7.40-kg object initially has 347 J of gravitational potential energy. Then an elevator lifts the object a distance of 20.6 m above its previous position. How much work did the elevator perform on the object?

Answers

Answer:

W = 1493.9 J = 1.49 KJ

Explanation:

The work done by the elevator on the object will be equal to the gain in is potential energy:

W = ΔP.E

W = mgΔh

where,

W = Work = ?

m = mass of object = 7.4 kg

g = 9.8 m/s²

Δh = gain in height = 20.6 m

Therefore,

W = (7.4 kg)(9.8 m/s²)(20.6 m)

W = 1493.9 J = 1.49 KJ

A 5 kg ball rolling at 1.0 m/s hits a 15 kg ball at rest. The balls stick together after the collision What is the
velocity of the two balls after the collision?

Answers

Answer:

0.25m/s

Explanation:

Given parameters

m₁  = 5kg

v₁ = 1.0m/s

m₂ = 15kg

v₂ = 0m/s

Unknown:

velocity after collision = ?

Solution:

Momentum before collision and after collision will be the same. For inelastic collision;

    m₁v₁ + m₂v₂  = v(m₁ + m₂)

Insert parameters and solve for v;

   5 x 1  + 15 x 0 = v (5 + 15 )

          5  = 20v

          v = [tex]\frac{5}{20}[/tex]   = 0.25m/s

HELP HURRY PLEASE
According to the law of reflection, if angle of incidence is 50, what is angle of reflection?
A. 45
B. 50
C. 25
D. 100

Answers

Answer:

50

Explanation:

The angle of reflection is 50 because angle of incidence is equal to the angle of reflection

Q1) An action exerted on an object which may change the object's
state of rest or motion defines
a. acceleration.
b. force.
c. mass.
d. Velocity.

Answers

Answer: force...

Explanation:

is it true or false that chemical change like baking a cake normally has a color change?​

Answers

False, chemical change in baking a cake does not change color. There are other properties involved besides color change like the fluffiness of the cake and the taste of the cake.
Some chemical changes cause color changes but not always

the inside surfaces of the glass inside thermos bottles are coated with aluminum to prevent energy transfers by

Answers

Answer:

radiation heat.

Explanation:

That is any heat that passes through the air, like the sun.

Answer:

radiation

Explanation: I’m sure

pls mark as brainliest if possible

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