A skateboarder starting from rest accelerates down a ramp at 2 m/s for 2 s. What is the final speed of the skateboarder?

Answer:

B. heat and kinetic energy

Explanation:

Heat is a form of energy that flows with respect to temperature difference. Thus, heat energy would flow from an object with higher temperature to that at lower temperature. It generally cascades from a high temperature body to lower temperature body through a medium or when in contact.

Kinetic energy is the energy that is inherent in a moving object. Thus, it can be converted to other forms or transferred between objects. Example, a moving object can transfer part of its kinetic energy to an object at rest on collision. This may cause the motion of the initial stationary object.

Therefore, heat and kinetic energy can be used to describe transfer of energy to or from a substance.

Explanation:

B. leads to muscle strain.

Answer:

The Equivalence Principle of Gravity

Explanation:

The fact that objects fall to earth at the same speed is called the Equivalence Principle of Gravity.

According to the Equivalence Principle of Gravity, all things fall at the same rate when there is little to no air resistance. The value of the acceleration caused by gravity is demonstrated by the force of gravity equation to be a constant that is independent of the mass of the item.

According to Einstein's equivalence principle, it is unnecessary to distinguish between gravitational and inertial forces because they are comparable in nature.

Therefore, the Equivalence Principle of Gravity states that all objects descend to Earth at the same rate.

To learn more about the Equivalence Principle of Gravity, refer to the link:

https://brainly.com/question/21136206

#SPJ2

Answer:

Velocity= Distance divided by time divided by degree or direction.

Explanation:

Speed=DIstance divided by time

Let θ₁ and θ₂ denote the angles made by the tension forces T₁ and T₂ with the positive horizontal axis (directly to the right), respectively. (BTW, I write T₁ in boldface for the vector and T₁ for its magnitude.)

The ball is kept in equilibrium, so by Newton's second law both the net horizontal and net vertical forces are zero. This means

[1]   T₁ cos(θ₁) + T₂ cos(θ₂) = 0

[2]   T₁ sin(θ₁) + T₂ sin(θ₂) - m g = 0

Both cos(x) and sin(x) fall within -1 and 1 for any angle x, so right away we know that

T₁ sin(θ₁) + T₂ sin(θ₂) ≠ T₁ + T₂

so option (B) is not correct.

If T₁ = T₂, then in equation [1] we get

T₁ cos(θ₁) + T₁ cos(θ₂) = 0

T₁ (cos(θ₁) + cos(θ₂)) = 0

cos(θ₁) + cos(θ₂) = 0

which means θ₁ = 180° - θ₂, since cos(180° - x) = - cos(x) for any x. But this would require both strings to have the same length. So option (C) is also not correct.

The horizontal components of T₁ and T₂ are the only forces acting in the horizontal direction, so their horizontal components are equal. However, the vertical component of T₂ is closer to being parallel to the weight of the ball, which means T₂'s vertical component is almost enough on its own to counteract the ball's weight. This in turn means that (D)T₂ > T₁.

In other words, sin(θ₂) is closer to 1 than sin(θ₁), and T₂ is closer to m g than T₁.

Answer:

5.5 to 7 Mohs

Explanation:

Glass ranks around 5.5 to 7 Mohs, but sapphire crystal has a hardness of 9 Mohs, making it only slightly less hard than diamond.

Answer: 5.5

Explanation:

Several hardness scales have been developed to catalog the materials (specifical minerals), being the Mohs scale the best known. This scale, proposed by the German geologist Friedrich Mohs in 1825, consists of a ratio of ten minerals numbered in increasing order by hardness, from least to greatest.

Answer:

Electricity?

Explanation:

Answer:

you do a chemical reaction thing

Explanation:

get baking soda and mix it with b

vinegar and then try other liquids on baking soda and see the reaction, make sure to document and take pictures

Answer:

The displacement is 145 m in the north direction and the distance is 355 miles.

Explanation:

The distance traveled by a mobile is the length of its trajectory and it is a scalar quantity. In other words, distance refers to the space traveled by an object during its movement. It is calculated as the sum of all the distances traveled. In this case:

250 miles + 105 miles= 355 miles

On the other hand, displacement refers to the distance from a start position to an end position regardless of the travel. That is, like distance, displacement is a measure of length. Instead, the displacement is a vector quantity that depends on the direction, so it is described from the magnitude and the direction.

Mathematically, the displacement d is calculated as:

d = df - di

where df is the final position and di is the initial position of the object.

In this case:

displacement= 250 miles - 105 miles= 145 miles

Since the north distance is greater than the south distance, then the displacement is 145 m in the north direction and the distance is 355 miles.

Answer:

Abstract

There are strong evidences linking physical outdoor activity and health benefits; however, little is known about the impact on environmental behaviors. Thus, this study aims to close this gap by investigating the influence of physical outdoor activity on environmental behaviors. A total of 416 surveys were distributed to students in eight public primary schools located near the Hsinchu Science and Industrial Park in Taiwan. Findings from the analysis revealed that subjective norms had a more influential effect on environmental behaviors for participants who engaged in physical activity at outdoor parks. In contrast, descriptive norms had a direct predictive impact on environmental behaviors for participants whose main physical activity venue was at the indoor after-school centers. Research results also highlighted attitude as the strongest predictive variable influence on environmental behaviors for children who engaged in physical indoor and outdoor activities

Explanation:

hula ko lng yan

Answer:

speed of object after 2 seconds will be 6 ms⁻¹

Explanation:

Initial velocity = 0

Final Velocity = 21 m/s

Time = 7 sec

We need to find speed of object after 2.0 seconds.

First we will find acceleration using formula: [tex]Accelaration=\frac{change \ in \ velocity}{change \ in \ time}[/tex]

Putting values:

[tex]Accelaration=\frac{Change \ in \ velocity}{Change \ in \ time}\\Accelaration=\frac{21-0}{7}\\Accelaration=\frac{21}{7}\\Accelaration= 3 \ ms^{-2}[/tex]

Now finding speed of object after 2 seconds

The formula used will be: [tex]Speed(v) = a\times t+v_0[/tex]

Putting values of a= 3m/s², t=2 sec and v₀=0 (at rest)

[tex]Speed(v) = a\times t+v_0\\Speed(v) = 3\times 2+0\\Speed(v) =6\ ms^{-1}[/tex]

So, speed of object after 2 seconds will be 6 ms⁻¹

Answer:

MA of a machine is always less than VR.

Explanation:

It is because mechanical advantage decreases due to the friction and weight of moving parts of the machine whereas the velocity ratio remains constant.

Answer:

In words, it could be said that the force times the time equals the mass times the change in velocity. In physics, the quantity Force • time is known as impulse. And since the quantity m•v is the momentum, the quantity m•Δv must be the change in momentum. The equation really says that the Impulse = Change in momentum.

Answer:

Explanation:

•Scientists have found that the rocks that make up the seabed are hidden in their "threads". This strip contains a record of the rotation of the Earth's magnetic field. The rocks on the seabed contain iron. ... When the rock cools down, the iron fragments inside align with the direction of the Earth's magnetic poles.

Answer:

b

Explanation:

9514 1404 393

Answer:

  12.  x = 11; sides are 29

  13.  x = 5; sides are 25

Explanation:

12. The marked sides are equal length, so ...

  3x -4 = 2x +7

  x = 11 . . . . . . . . add 4-2x

  2x+7 = 2(11)+7 = 29 . . . side lengths

__

13. The marked sides are equal length, so ...

  6x -5 = 5x

  x = 5 . . . . . . . add 5-5x

  5x = 5(5) = 25 . . . side lengths

Answer:

1351.62 Watts.

Explanation:

The following data were obtained from the question:

Mass (m) = 79.5 kg

Height (h) = 2.29 m

Time (t) = 1.32 s

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

Power =?

Next, we shall determine the potential energy of the boy. This can be obtained as follow:

Potential energy (PE) = mass × acceleration × height

PE = m × g × h

Mass (m) = 79.5 kg

Height (h) = 2.29 m

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

Potential energy (PE) =?

PE = m × g × h

PE = 79.5 × 9.8 × 2.29

PE = 1784.139 J

Finally, we shall determine the power generated by Andrew as illustrated below:

Energy (E) = 1784.139 J

Time (t) = 1.32 s

Power (P) =?

P = E/t

P = 1784.139 /1.32

P = 1351.62 watts

Therefore, the power generated by Andrew was 1351.62 watts

Answer:

The final velocity of the bullet is approximately 3.795 m/s

Explanation:

The given parameters are;

The mass of the bullet, m = 5.0 g

The force applied to the bullet, F = 45 N

The distance over which the force is applied, d = 0.80 m

Therefore, we have;

The final kinetic energy of the bullet = = 1/2 × m × v² = The work done on the bullet by the 45 N force = F × d

Where;

v = The final velocity of the bullet

By substitution, we get;

The final kinetic energy of the bullet = 1/2 × 5.0 × v² = 45 × 0.8

1/2 × 5.0 × v² = 45 × 0.8

v² = (45 × 0.8)/(1/2 × 5.0) = 14.4

v = √14.4 ≈ 3.795

The final velocity of the bullet = v ≈ 3.795 m/s

Answer:

shut up

Explanation:

and watch the video lazy bum

Answer:

To help push yourself to reach the goal, It can also help you pace yourself time wise

Explanation:

Explanation:

an echo mimics exactly what is said, this is like a mirror because when you look in a mirror every action you make is copied by your reflection

depends on how high the school is. how high is it?

Explanation:

When the mass of the cannon increases and the energy of the blast remains the same, the total kinetic energy remains the same.

Kinetic energy refers to the form of energy that an object possesses due to its motion. It is known as the work that's required to move a body.

It should be noted that when there is an increase in the mass of the cannon while the energy of the blast remains the same, then in such a situation, the total kinetic energy will remain the same.

Read related link on:

https://brainly.com/question/19017247

Answer:

There are two reasons why air pressure decreases as altitude increases: density and depth of the atmosphere. Most gas molecules in the atmosphere are pulled close to Earth's surface by gravity, so gas particles are denser near the surface.

Explanation:

Answer:

1.6L

Explanation:

Given parameters:

Initial volume  = 1.5L

Initial temperature  = 5°C  = 5 + 273  = 278K

Final temperature  = 30°C = 30 + 273  = 303K

Unknown:

Final or new volume  = ?

Solution;

Since pressure is constant, we simply apply Charles's law to solve this problem.

Using the expression below,

          [tex]\frac{V_{1} }{T_{1} }[/tex]   = [tex]\frac{V_{2} }{T_{2} }[/tex]

V and T are volume and temperature

1 and 2 are initial and final states

  Insert the parameters and solve;

         [tex]\frac{1.5}{278}[/tex]   = [tex]\frac{V_{2} }{303}[/tex]

          278V₂  = 1.5 x 303

                V₂  = 1.6L