According to a rule-of-thumb. every five seconds between a lightning flash and the following thunder gives the distance to the f
1 answer:
Answer:
The rule for kilometers is that every three seconds between a lightning flash and the following thunder gives the distance to the flash in kilometers.
Explanation:
In order to use the rule of thumb to find the speed of sound in meters per second, we need to use some conversion ratios. We know there is 1 mile per every 5 seconds after the lightning is seen. We also know that there are 5280ft in 1 mile and we also know that there are 0.3048m in 1ft. This is enough information to solve this problem. We set our conversion ratios like this:
notice how the ratios were written in such a way that the units got cancelled when calculating them. Notice that in one ratio the miles were on the numerator of the fraction while on the other they were on the denominator, which allows us to cancel them. The same happened with the feet.
The problem asks us to express the answer to one significant figure so the speed of sound rounds to 300m/s.
For the second part of the problem we need to use conversions again. This time we will write our ratios backwards and take into account that there are 1000m to 1 km, so we get:
This means that for every 3.11s there will be a distance of 1km from the place where the lightning stroke. Since this is a rule of thumb, we round to the nearest integer for the calculations to be made easily, so the rule goes like this:
The rule for kilometers is that every three seconds between a lightning flash and the following thunder gives the distance to the flash in kilometers.
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Answer:
The velocity of the proton is
Explanation:
The momentum of a particle is defined as the product of its mass by its velocity and we can calculate it using the following formula:
p=m*v Equation (1)
Where:
p: Is the momentum in kg*m/s
m: Is mass of the particle in kg
v: Is the velocity of the particle in m/s
Data known:
m= 1,6726 × 10^–27 kg : mass of the proton
p= 4.96 X 10^-19 kg.m/s.
We replace this data in the Equation (1):
Answer: The velocity of the proton is
Answer:
Case 1: <u>Pushing</u> Diagram 1
Leaning over and Pushing the heavy box from the floor, the push will be divided in to two parts, one is horizontal that can help the box move, and one is vertically downwards, which increases the downward force of the heavy object (an addition to the gravity) and thus increases friction, making it very hard to push. When you push at certain angle, you are exhibiting two forces as shown in diagram 1.
- Horizontal force acting along the plane.
- Vertical force downward perpendicular to the surface.
Case 2: <u>Pulling</u> Diagram 2
Pulling on a rope similar object at the same angle, the pull can be divided into two parts, one is horizontal that can help the box move, and one is vertically upwards, which decreases the downwards force of the box (a subtraction in the gravity) and thus decreases friction, making it very easy to pull. When you pull at a certain angle, you are exhibiting two forces as shown in diagram 2.
- Horizontal force acting along the plane.
- Vertical force upward perpendicular to the surface.
So, in the case of pushing, it adds an extra weight on the object, which results in difficulty to push that object at the same angle. In case of pulling, the upward perpendicular force, it tries to lift the object upward and divided the weight partially. Thus making it easier to move the object at same angle.
