<span>Rills, gullies, streams, rivers and tributaries are all caused by water erosion. Water erosion is the natural act by which water flow (or wind flow) slowly removes soil, rock, or any material found in the earth's crust. The removed materials are transported to another location, leaving behind changes in the crust.</span>
Answer:
C. Experimental Probability
Explanation:
The empirical (or experimental) probability means the event that arise and depend how the event arise when the data is collected from an experiment in a more no of trials. It would be depend upon the direct observation. Here each and every observation in an experiment is known as trial
So the probability that depend upon the experiment observation is known as the experimental probability
Hence, the option c is correct
Answer:
Incomplete question. Complete question is: An electric drill starts from rest and rotates with a constant angular acceleration. After the drill has rotated through a certain angle, the magnitude of the centripetal acceleration of a point on the drill is twice the magnitude of the tangential acceleration. Determine the angle through which the drill rotates by this point.
The answer is : Δ θ = 1 rad
Explanation:
Ok, so the condition involves the centripetal acceleration and the tangential acceleration, so let’s start by writing expressions for each:
Ac= centripetal acceleration At= tangential acceleration
Ac = V² / r At = r α
Because we have to determine the angle ultimately, therefore we should convert the linear velocity into angular velocity in the expression for centripetal acceleration
V = r ω
Ac = (r ω)² / r = r² ω² / r
Ac = r ω²
now that we have expressions for the centripetal and tangential acceleration, we can write an equation that expresses the condition given: The magnitude of the centripetal acceleration is twice the magnitude of the tangential acceleration.
Ac = 2 At
That is,
r ω² = 2 r α
it is equivalent to;
ω² = 2 α
now we have the relation between angular speed and angular acceleration, but we also need to determine the angular displacement as well. Therefore choose a kinematics equation that doesn’t involve time because time is not mentioned in the question. Thus,
ω² – ω°² = 2 α Δ θ
such that ω° = 0
and ω² = 2 α
therefore;
2 α - 0 = 2 α Δ θ
2 α = 2 α Δ θ
So the angle will be : Δ θ = 1 rad
Answer:
C) Contact
Explanation:
The magnet requires almost direct <u>contact</u> with the fridge to start its magnetic properties.
Here are the parts of the comet:
1. NUCLEUS: This is the frozen part of the comet. It is also known as the core. It is made up of ice and dust which are completely covered by organic matter. The nucleus usually consist of frozen water but other materials that are in frozen forms can be found in it. Comet nuclei are usually less than 16 kilometer in diameter.
2. COMA: The atmosphere of dust and gases formed when the nucleus vaporize. The coma refers to the envelope of gases that surround the comet's nucleus. The coma plus the nucleus forms the head of the comet. The coma is about a million kilometer in diameter and is made up of gases and dust which sublime from the comet's nucleus.
3. ION TAIL: Tail made of ions that appear to point away from the comet's orbit. The charged solar particles convert the gases found in the comet to ions thus forming an ion tail. The ion tail can measure over 100 million kilometer long and it accelerate much faster than the dust tail.
4. DUST TAIL: Tail made up of small solid dust particles. It is formed by radiation from the sun, which forces dust particles away from the coma. It usually point away from the sun because the tail are shaped by the solar wind. As the distance from the sun increases, the dust tail usually become faint and diminished.
