Answer: B. Allegheny plateau
Explanation: Allegheny plateau is a mountainous region that makes up the northern part of the United States of America, the following states are located on the Allegheny plateau New York, Pennsylvania, West Virginia and Ohio, it is made up of HORIZONTAL SEDIMENTARY BEDROCK at elevated lands. Allegheny plateau is over 40million area is over 40million acres,it has been a site for Erosion and for millions years,through this erosions some areas have been brought low while others are higher following the deposition of materials by the erosion.
Answer:
the mass of the truck is 2 kg.
Explanation:
Given;
mass of the car, m₁ = 3 kg
initial velocity of the car, u₁ = 40 m/s
initial velocity of the truck, u₂ = 60 m/s
let the mass of the truck = m₂
Apply the principle of conservation of linear momemtum;
m₁u₁ = m₂u₂
m₂ = (m₁u₁) / u₂
m₂ = (3 x 40) / (60)
m₂ = 2 kg
Therefore, the mass of the truck is 2 kg.
<h2>
Answer: a.The mirrors and eyepiece of a large telescope are spring-loaded to allow them to return quickly to a known position. </h2>
Explanation:
Adaptive optics is a method used in several astronomical observatories to counteract in real time the effects of the Earth's atmosphere on the formation of astronomical images.
This is done through the insertion into the optical path of the telescope of sophisticated deformable mirrors supported by a set of computationally controlled actuators. Thus obtaining clear images despite the effects of atmospheric turbulence that cause the unwanted distortion.
It should be noted that with this technique it is also necessary to have a moderately bright reference star that is very close to the object to be observed and studied. However, it is not always possible to find such stars, so a powerful laser beam is used to point towards the Earth's upper atmosphere and create artificial stars.
There is still air inside of a house, which is pushing the roof upwards, so the forces are equal and the roof is not crushed.
