What must happen to an object in order to accelerate it?

Answer:

b. at the top

Explanation:

At the top of the climb, the vertical velocity of Jeff's throw has a value of zero.

Vertical velocity in this instance is acting against the acceleration due to gravity.

Answer:

Explanation:

The velocity can be found by using the formula

[tex]v = \sqrt{ \frac{2k}{m} } \\ [/tex]

k is the kinetic energy

m is the mass

From the question we have

[tex]v = \sqrt{ \frac{2 \times 4116}{4200} } \\ = 1.4[/tex]

We have the final answer as

Hope this helps you

Answer:

The speed of the lift is 1.4 m/s

Explanation:

Kinetic Energy

Is the type of energy of an object due to its motion. It's proportional to the square of the speed and the mass.

The equation for the kinetic energy is:

[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]

Where:

m = mass of the object

v = speed at which the object moves

The kinetic energy is expressed in Joules (J)

It's given the mass of the lift as m=4,200 kg and its kinetic energy K=4,116 J. To calculate the speed (magnitude of velocity), we solve the formula for v as follows:

[tex]\displaystyle v=\sqrt{\frac{2k}{m}}[/tex]

[tex]\displaystyle v=\sqrt{\frac{2*4,116}{4,200}}[/tex]

[tex]\displaystyle v=\sqrt{1.96}[/tex]

v = 1.4 m/s

The speed of the lift is 1.4 m/s

Answer:

The higher the skater is the more potential energy he has. As his height decreases, his potential energy decreases and his kinetic energy increases.

Explanation:

Make me BRAINLIST please

Answer:

The higher the skater is the more potential energy he has. As his height decreases, his potential energy decreases, and his kinetic energy increases. ... Explore how the skater's change in speed relates to the potential and kinetic energy of the skater.

Explanation:

(Via Uteach)

The centripetal force is the force that keeps a body moving in a circular path.

The centripetal force is given by; F = mv^2/r

1) We have;

F = 5,600 N

v = 20 m/s

r =?

m = 700 kg

Making r the subject of the formula;

r =mv^2/F

r = 700 × (20)^2/5,600

r = 50 m

2) F = mv^2/r

F = 900 × (5)^2/30

F = 750 N

3) Making r the subject of the formula;

r =mv^2/F

r = 800 × (40)^2/ 16,000

r = 80 m

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Answer:

No work is done since no distance is given

Explanation:

Since no distance is given, the force is not doing any work

No work is done by the man since we do not know the distance or displacement.

Work is only said to be done when the force applied on an object moves it through a particular distance.

Work done  = Force x distance.

Since no distance is given in this problem, we can as well assume that the force applied is doing no work on the object.

Answer:

If you going to ask a question ask it accurately.

Explanation:

Answer:

I’m. Nog sure

Explanation:

Answer:

A. White light is the absence of all color.

Explanation:

It is false that white light is the absence of all color. In fact, white light is the presence of all colors in the spectrum.

Electromagnetic waves are waves that do not require any material medium for propagation. It is the interaction of electric and magnetic fields.

Naw ur pretty accurate, heck collage is the only football worth watching most the time. Hook'um horns!

Answer:

gases.

Explanation:

gases have the highest volume. if you compress (increase pressure) a gas, the volume decreases and it will take up less space as a liquid, and if you compress more, the liquid will become a solid.

additionally info: this is generally true, but as you get into more difficult subjects, this rule does not hold. for example, some substances cannot obtain a certain phase of matter when they are a certain temperature and or pressure. but that could be way more out of this questions league.

Answer:

Concave lens spreads out light rays that are then refracted through it.: A concave mirror or a converging lens will only produce a virtual image at a point if the image is located beyond the focal point. By the focal point, we define the point that is more than one focal length away.

Answer:

39225J

Explanation:

Given parameters:

Mass of water  = 375grams of water

Change in temperature  = 25°C

Specific heat capacity of water  = 4.184J/g°C

Unknown:

Amount of heat absorbed  = ?

Solution:

To solve this problem, we use the expression below:

      H  = m c Ф  

H is the heat absorbed

m is the mass

c is the specific heat capacity

Ф is the change in temperature

  Insert the parameters and solve;

      H  = 375 x 4.184 x (25) = 39225J

Answer:

D is the correct answer

Explanation:

Ek=m*g*h=50*9.8*5=2450

The kinetic energy right before she hits the water is 2450J. So, the correct option is D.

Kinetic energy is defined as the energy that is due to the motion of an object. If we want to accelerate an object, we must apply a force, by applying a force we need to do work. After the work is done, energy has been transferred to the object, and the object will continue to move with a new constant speed.

A 50Kg girl jumps off a 5-meter-high diving board.

We need to find the kinetic energy of the girl before she enters the water which means that the kinetic energy becomes equal to the potential energy such that,

P.E.=K.E. = mgh

where, m=mass of the object

g= acceleration due to gravity [tex](9.8m/s^2)[/tex]

h= height

So, K.E= 50* 9.8*5 = 2450 J

Thus, the kinetic energy right before she hits the water is 2450J. So, the correct option is D.

Learn more about Kinetic energy, here:

https://brainly.com/question/21505162

#SPJ2

Answer:

Explanation:

El campo eléctrico provocado por una carga puntal sobre determinado punto viene dado por la ecuación:

E  = K * Q /r²       en esa ecuación E es el campo eléctrico (un vector), K es una constante K = 1/4*π*ε₀   Q es la carga que origina el campo, y r la distancia entre la carga y el punto donde se quiere determinar el campo. La fuerza de origen eléctrico y el campo eléctrico van en la dirección de la recta de unión entre carga y punto ( es decir según r) y esta fuerza sera repulsiva o de atracción según que la carga que la origina sea positiva o negativa (respectivamente, ya que en la determinación de fuerza y campo, se asume que se coloca una carga de prueba positiva en el punto ).

Siendo así, si dos cargas elécticas son iguales y están separadas una distancia r ; en el punto medio (r/2) los campos producidos por cada una de las cargas serán de la misma magntud.

Carga Q₁  = Carga Q₂  = Q

E₁ = K * Q₁ / (r/2)²   y    E₂  = K * Q₂/(r/2)²

Y además tendran direcciones totalmente opuestas, por lo que se anularan

En el segundo caso las cargas son iguales en magntud pero de diferentes signos ( una positiva y la otra negativa ). En este caso los campos eléctricos continuaran siendo de la msma magnitud pero dado que la carga positiva repele la carga de muestra (teorica) y la negativa la atrae los dos campos coinciden en su dirección y resultará una campo de magnitud doble. La dirección del campo será en la tendencia de acercarse a la caga negativa, así si la carga negativa está a la derecha la fuerza de origen eléctrico y el campo van hacia la derecha y si la carga negativa está a la izquierda pues esa será la diercción del campo

Answer:

Heat vs temperature - Energy Education The core difference is that heat deals with thermal energy, whereas temperature is more concerned with molecular kinetic energy. Heat is the transfer of thermal energy, whereas temperature is a property the object exhibits.

element z are isotopes because number of netron are different and number of protons are same

Complete question :

A flight attendant pulls her 70 N flight bag a distance of 318 m along a level airport floor at a constant velocity. The force she exerts is 41 N at an angle of 57° above the horizontal.

(a) Find the work she does on the flight bag.

(b) Find the work done by the force of friction on the flight bag.

(c) Find the coefficient of kinetic friction between the flight bag and the floor.

Answer:

7107 J ; - 7107 J ; 0.55

Explanation:

Given that :

Distance, d = 318m

Applied force = 41 N

θ = 57°

A.) Workdone = Force exerted along direction of motion

Workdone = applied Force * distance * cosθ

Workdone = 41 * 318 * cos57 = 7101.0037

Workdone = 7,101 J

B.) Workdone by force of friction on flight bag:

- 7,101 J (since the body moves at constant velocity)

C.)

Coefficient of kinetic friction (μ) = Frictional force / normal reaction)

μ = F / N

Frictional force, F = Workdone by friction / distance

F = 6200 / 318

F = 19.47N ;

Ff = weight of Flight bag = 70 N

N = Ff - Fsinθ

N = 70 - applied Force sinθ

N = 70 - 41sin57

N = 70 - 34.385493

N = 35.614506

μ = 19.47 / 35.614506

μ = 0.5466873

Explanation:

600 ÷ 60 = 10

1500 ÷ 10 = 150 minutes

I don't know how you should express the answer in:

So it's either 150 minutes or 2 hours and 30 minutes.

(This is kind of like mathematics, not physics)

Answer:

A convex lens or converging lens focuses the light rays to a specific point whereas a concave lens or diverging lens diverges the light rays. When these lenses are combined, they produce sharper images. Most of the eyeglass lenses use combinations of convex and concave lenses.

Answer:

Total time elapsed between the start and when he returns with the ball is 7.5s

Explanation:

From the question,

- The dog starts at the origin and runs forward at 6m/s for 1.5s. First, we will determine the distance covered while running forward.

From

Speed = Distance / Time

Distance = Speed × Time

Speed = 6m/s

Time = 1.5s

∴ Distance = 6m/s × 1.5s

Distance = 9m

That is, the dog covered a distance of 9m while running forward.

- The dog turns around and runs backward at 7m/s for 3s. Now, we will also determine the distance the dog covered backwards.

Distance = Speed × Time

Speed = 7m/s

Time = 3s

Distance = 7m/s × 3s

Distance = 21m

The dog's displacement from the origin is 21m - 9m = 12m

Now, to calculate how much time has elapsed between the start if the dog runs back to the origin at 4m/s, we will first determine the time the dog spent back to the origin and then add to the time spent for the first two distances.

To get back to the origin, the dog needs to cover 12m

From

Speed = Distance / Time

Time = Distance / Speed

Distance = 12m

Speed = 4m/s

∴ Time = (12m) / (4m/s)

Time = 3s

Therefore, the dog spent 3s to run back to the origin.

Hence, total time elapsed = 1.5s + 3s + 3s

Total time elapsed = 7.5s

Answer:

An object at rest is described by Newton's First Law of Motion. An object in static equilibrium has zero net force acting upon it. The First Condition of Equilibrium is that the vector sum of all the forces acting on a body vanishes.

Explanation:

Answer:

see below

Explanation:

the first condition means that the light ray inside the optically denser medium hits the surface of the optically less dense medium.

this in simple words means, light must be travelling from am optically denser medium to an optically less dense medium

hope this helps :)

Answer:

8.3m/s

Explanation:

Given parameters:

mass of clay ball  = 5kg

Speed of clay ball  = 25m/s

mass of clay ball at rest  = 10kg

speed of clay ball at rest  = 0m/s

Unknown:

Velocity after collision  = ?

Solution:

 Since the balls stick together, this is an inelastic collision:

   m1v1 + m2v2  = v(m1 + m2)

  5(25) + 10(0)  =  v (5 + 10)

         125 = 15v

           v  = 8.3m/s

Answer:

38.75N

Explanation:

According to Newton's second law

\sum Fx = ma

Fm-Ff = ma

Fm is the moving force

Fm = mgsin theta

Fm = 15(9.8)sin38

Fm = 90.5N

Ff is the frictional force

m is the mass = 15kg

a is two acceleration

Get the acceleration

a= F/m

a = 52/15

a ,= 3.45m/s²

Substitute the given values into the formula

90.5-Ff = 15(3.45)

90.5-Ff = 51.75

Ff = 90.5-51.75

Ff = 38.75N

Hence the frictional force on the box is 38.75N

Answer:

1.  -0.863 kgm/s 2. -1.438 kgm/s

Explanation:

1. What is the change in momentum of the bullet if it embeds in the block?

Since the block does not move, the velocity of the bullet after hitting the block , v is zero. That is v = 0 m/s

Now, the momentum change of the bullet ΔP = m(v - u) where m = mass of block = 5.75 g = 5.75 × 10⁻³ kg, u = initial velocity of bullet = 1.50 × 10² m/s and v = final velocity of bullet after hitting the block = 0 m/s (since it embeds in the block and the block does not move).

So, ΔP = m(v - u)

= 5.75 × 10⁻³ kg(0 m/s - 1.50 × 10² m/s)

= 5.75 × 10⁻³ kg(- 1.50 × 10² m/s)

= -8.625 × 10⁻¹ kgm/s

= -0.8625 kgm/s

≅ -0.863 kgm/s

2. What is the change in momentum of the bullet if it bounces off the block in the opposite direction with a speed of 100 m/s?

If it bounces off the block in the opposite direction with a speed of 100 m/s, then its final velocity is v = -100 m/s.

So, our momentum change ΔP' = m(v - u) where m = mass of block = 5.75 g = 5.75 × 10⁻³ kg, u = initial velocity of bullet = 1.50 × 10² m/s and v = final velocity of bullet after hitting the block = -100 m/s = -1 × 10² m/s

So, ΔP = m(v - u)

= 5.75 × 10⁻³ kg(-1 × 10² m/s - 1.50 × 10² m/s)

= 5.75 × 10⁻³ kg(-2.50 × 10² m/s)

= -14.375 × 10⁻¹ kgm/s

= -1.4375 kgm/s

≅ -1.438 kgm/s

Answer: C: The moons orbit around the earth.

Explanation: