How are forces able to act at a distance ?

Answer:

V = 20.5 m/s

Explanation:

Given,

The mass of the cart, m = 6 Kg

The initial speed of the cart, u = 4 m/s

The acceleration of the cart, a = 0.5 m/s²

The time interval of the cart, t = 30 s

The final velocity of the cart is given by the first equation of motion

                              v = u + at

                                  = 4 + (0.5 x 30)

                                = 19 m/s

Hence the final velocity of cart at 30 seconds is, v = 19 m/s

The speed of the cart at the end of  3 seconds

                                    V = 19 + (0.5 x 3)

                                       = 20.5 m/s

Hence, the final velocity of the cart at the end of this 3.0 second interval is, V = 20.5 m/s

Answer:

The speed of a turtle is 4m/s

Explanation:

speed = distance/time

distance = 100m

time = 25s

s = 100/25

= 4m/s

3. The Earthquake occured on the other side of the Earth

Explanation:

One of the main difference between P-waves and S-waves is that P-waves can travel through solids and liquids, while S-waves can only travel through solids. They are not able to travel through liquids.

So, if a seismic station showed only P waves, it means that there was some area in liquid state between the seismic station and the hypocenter of the earthquake. Inside the Earth, the outer part of the core is made of liquid, so this means that there outer core was along the line connecting the seismic station and the hypocenter and "blocked" the S-waves: therefore, the earthquake occurs on the other side of the Earth.

4. In order to determine with precision the location of the epicenter

Explanation:

One seismic station is only able to determine the distance of the epicenter - so, by using one seismic station only, we are only able to tell that the epicenter is located on a point along a circle, centered around the seismic station.

If we use two seismic station located at different points, we can draw two circles of possible locations for the epicenter, one for each seismic station. The intersection between the two circles will give us the exact location of the epicenter. However, two circles have two intersections: therefore, there is still an ambiguity concerning the exact location of the epicenter.

If we use three stations, therefore, we can draw three circles, and they have one intersection only: this intersection will give us the exact location of the epicenter.

Answer:

1. P waves can travel through liquid and solids and gases, while S waves only travel through solids. Scientists use this information to help them determine the structure of Earth. For example, if an earthquake occurs on one side of Earth, seismometers around the globe can measure the resulting S and P waves.

2. P waves can travel through liquid and solids and gases, while S waves only travel through solids. Scientists use this information to help them determine the structure of Earth. For example, if an earthquake occurs on one side of Earth, seismometers around the globe can measure the resulting S and P waves.

3. If a seismogram records P-waves and surface waves but not S-waves, the seismograph was on the other side of the Earth from the earthquake because those waves cannot travel through the liquid core of the earth.

4. Scientists use triangulation to find the epicenter of an earthquake. When seismic data is collected from at least three different locations, it can be used to determine the epicenter by where it intersects. Knowing this helps them calculate the distance from the epicenter to each seismograph.

5. As the P and S waves travel out from an earthquake the P waves get progressively farther ahead of the S waves. Therefore, the farther a seismic recording station is from the earthquake epicenter the greater will be the difference in time of arrival between the P and S wave.