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2 years ago

If the kinetic energy of a given mass is to be doubled, its speed must be multiplied by

Physics

1 answer:

Tomtit [17]2 years ago

3 0

Answer:

Either B or D. The answer itself is 2.

Explanation:

The equation for the kinetic energy would be 1/2*mv^2.

When m is doubled, we can plug in 1 and 2 to compare our answers.

Plugging in 1 for mass would give us the answer 1/2*v^2.

Plugging in 2 for mass would give us v^2. This means that the velocity was multiplied by 2, meaning that the answer is it is multiplied by 2.

I am not sure which answer is correct since there seems to be two answer choices with 2 in it, but the answer is either B or D (I will call it ABCD because I do not want to cause confusion by saying 2 multiple times).

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A student who was training for a cross country race jogged for 2. 0 hours and covered a distance of 14. 0 kilometers. What was t

FinnZ [79.3K]

The average speed is 116.66m/s.

Given - The path traced is 14km , time for jogging is 2 hrs=120min

To find the average speed-

Speed refers to the ease of the movement and degree of mobility as a result of force application.
Due to this there is involvement of velocity.
Journey of average speed is the cumulative of distances and time.
Kinetic theory refers to the Boltzmann constant connecting to the standards of distance traversed.

calculations-

$Speed= \frac{Distance}{Time}$

Speed= 14 000 / 120

= 116.66m/s

To learn more about average speed -

brainly.com/question/27753148

#SPJ4

6 0

11 months ago

Check all of the following statements that describe velocity.

Nata [24]

Answer:

Choices A, B, and C are correct.

Explanation:

Let us look at each of the choices one by one:

A. It is a vector

Yes. Velocity is a vector, or it's a speed with direction.

B. It is the change in displacement divided by the change in time.

Yes. The velocity can be written as

$v = \dfrac{\Delta\bold{x}}{\Delta t}$

where $\bold{x}$ is the displacement—a vector quantity.

C. It can be measured in meters per second.

Yes. The units of velocity are m/s, but also with a unit vector indicating the direction.

D. It is the slope of the acceleration vs. time graph.

Nope. The velocity is the slope of displacement vs. time graph.

Hence, only choices A, B, and C are correct.

4 0

2 years ago

To determine the muzzle velocity of a bullet fired from a rifle, you shoot the 2.47-g bullet into a 2.43-kg wooden block. The bl

Elza [17]

Answer:

The velocity of the bullet on leaving the gun's barrel is 236.36 m/s.

Explanation:

Given;

mass of the bullet, m₁ = 2.47 g = 0.00247 kg

mass of the wooden block, m₂ = 2.43 kg

initial velocity of the wooden block, u₂ = 0

height reached by the bullet-block system after collision = 0.295 cm = 0.00295 m

let the initial velocity of the bullet on leaving the gun's barrel = v₁

let final velocity of the bullet-wooden block system after collision = v₂

Apply the principle of conservation of linear momentum;

Total initial momentum = Total final momentum

m₁v₁ + m₂u₂ = v₂(m₁ + m₂)

0.00247v₁ + 2.43 x 0 = v₂(2.43 + 0.00247)

0.00247v₁ = 2.4325v₂ -------(1)

The kinetic energy of the bullet-block system after collision;

K.E = ¹/₂(m₁ + m₂)v₂²

K.E = ¹/₂ (2.4325)v₂²

The potential energy of the bullet-block system after collision;

P.E = mgh

P.E = (2.4325)(9.8)(0.00295)

P.E = 0.07032

Apply the principle of conservation of mechanical energy;

K.E = P.E

¹/₂ (2.4325)v₂² = 0.07032

1.21625 v₂² = 0.07032

v₂² = 0.07032 / 1.21625

v₂² = 0.0578

v₂ = √0.0578

v₂ = 0.24 m/s

Substitute v₂ in equation (1), to obtain the initial velocity of the bullet;

0.00247v₁ = 2.4325v₂

0.00247v₁ = 2.4325 (0.24)

0.00247v₁ = 0.5838

v₁ = 0.5838 / 0.00247

v₁ = 236.36 m/s

Therefore, the velocity of the bullet on leaving the gun's barrel is 236.36 m/s.

5 0

2 years ago

Calculate the final speed of a 110-kg rugby player who is initially running at 8.00 m/s but collides head-on with a padded goalp

Contact [7]

The answer is -0.8 m/s. We know acceleration is the average of final minus initial velocity over time (a = (vf-v0)/t). We also know that Force is equal to Mass times Acceleration (F = ma). Using our force equation, we know that the acceleration we get is negative 8.8 (-8.8). The force is acting in the opposite direction of the rugby player, hence the negative sign. From there, plug in that number for a in the velocity equation, and solve for vf, as v0 and t are known. We get 0.8 m/s in the opposite direction that the player was running.

6 0

2 years ago

Una motocicleta viaja con una velocidad constante de 72m/s calcula su velocidad en km/h

Juliette [100K]

Answer:

Entonces la velocidad de la motocicleta es $259.18 \frac{km}{h}$

Explanation:

La regla de tres simple es una operación que ayuda a resolver rápidamente problemas de proporcionalidad, teniendo tres valores conocidos y una incógnita.

Dos magnitudes son directamente proporcionales cuando al multiplicar o dividir una de ellas por un número, la otra queda multiplicada o dividida respectivamente por el mismo número. En otras palabras, dos magnitudes son directamente proporcionales si cuando aumenta una magnitud, también lo hace la otra en la misma proporción o cuando disminuye una magnitud, también lo hace la otra en la misma proporción.

Para resolver una regla directa de tres cuando las magnitudes son directamente proporcionales, se debe seguir la siguiente fórmula:

a ⇒ b

c ⇒ x

Entonces $x=\frac{c*b}{a}$

La regla directa de tres simple es la regla que se aplica en este caso donde hay un cambio de unidades. Para realizar esta conversión de unidades, primero debe saber que 1 m = 0.001 km. Entonces, si 0.001 km es 1 m, ¿cuántos kilómetros son 72 m?

$km=\frac{72 m*0.001 km}{1 m}$

km=0.072

Entonces:

$72\frac{m}{s} =\frac{72 m}{s} =\frac{0.072 km}{s}$

Siendo 1 s=0.0002778 h:

$72\frac{m}{s} =\frac{72 m}{s} =\frac{0.072 km}{s}=\frac{0.072 km}{0.0002778 h}=259.18 \frac{km}{h}$

Entonces la velocidad de la motocicleta es $259.18 \frac{km}{h}$

8 0

2 years ago