<h2>The hiker will go up to 850 m on the hill</h2>
Explanation:
The total energy gained by the hiker = 140 x 4186 J
This energy is consumed in the potential energy acquired , while climbing up the hill.
The potential energy P.E = mass of hiker x acceleration due to gravity x height
Thus
140 x 4186 = 69 x 10 x h
or h = 
= 850 m
If the 20% of the total energy is used
the height h₀ = 
= 170 m
For this case we have that by definition:
Where,
- <em>m: mass of the object
</em>
- <em>a: acceleration of the object
</em>
- <em>F: summation of forces
</em>
We have then:
Then, by clearing the acceleration we have:
Substituting values we have:
Answer:
The acceleration of the box is equal to:
The ball is against the vector of gravity. Then, the gravity will be negative.
The ball will stop in the air after approx. 4.72 seconds. And will take the same time to hit the ground.
It will stay approx. 9.44 seconds in the air.
Answer:
42 degrees, virtual image, same size as the object (26 cm)
Explanation:
The law of reflection states that:
- When a ray of light is incident on a flat surface (such as the plane mirror), the angle of reflection is equal to the angle of incidence
So, since in this case the angle of incidence is 42 degrees, the angle of reflection is also 42 degrees.
Moreover, the image formed by a plane mirror is always:
- Virtual (on the same side as the object)
- The same size as the object
So in this case, since the object's size is 26 cm, the image's size is also 26 cm.
Answer:
times
Explanation:
First of all, we need to write both the age of the universe and the lifetime of the top quark in scientific notation.
Age of the universe:
(1 followed by 17 zeroes)
Lifetime of the top quark:
(we moved the decimal point 24 places to the right)
Therefore, to answer the question, we have to calculate the ratio between the age of the universe and the lifetime of the top quark:
