Answer:
Our atmosphere has five different layers. They are:
1. Troposphere: This is the most important layer of the atmosphere with an average height of 13 km from the earth. It is in this layer that we find the air that we breathe. Almost all the weather phenomena such as rainfall, fog and hailstorm occur here.
2. Stratosphere: This layer extends up to a height of 50 km. It presents the most ideal condition for flying airplanes. It contains a layer of ozone gas which protects us from the harmful effect of the sun rays.
3. Mesosphere: This layer extends up to a height of 80 km. Meteorites bum up in this layer on entering from the space.
4. Thermosphere: In this layer, the temperature rises very rapidly with increasing height. The ionosphere is a part of this layer. It extends between 80-400 km. This layer helps in radio transmission. Radio waves transmitted from the earth the reflected back to the earth by this layer.
5. Exosphere: It is the uppermost layer where there is very thin air. Light gases such as helium and hydrogen float into space from here.
<h2>Right answer: It follows a curved path
</h2>
The movement of a projectile is a movement in two dimensions (forming a curved path: a parabola shape) with <u>constant acceleration.
</u>
<u>
</u>
A projectile is any body or object that is thrown or projected by means of some force and continues in motion by its own inertia. This means the only force that acts on it while in motion is <u>the acceleration of gravity</u> (in this case we are on Earth, so the gravity value is 
).
Where gravity influences the <u>vertical movement</u> of the projectile, while <u>the horizontal movement</u> of the projectile is the result of the tendency of any object to remain in motion at a constant speed (according to Newton's 1st law of motion sometimes called Law of Inertia).
The other options are <u>incorrect</u> because are <u>false</u>:
-The forward motion negates air resistance: There is always at least a small percent of air resistance, as long as that movement is done on Earth.
-It has variable acceleration: In projectile motion acceleration is constant (gravity acceleration)
.
-It is unaffected by gravity: The only force that acts on the projectile is due gravity.
Answer:
0.34s, 8.5m,31.89m
Explanation:
The above motion defines a projectile motion.
Now the athletes lands on a cliff 30° to the horizontal this means the velocity at that point would be 25m/s cos30°
Now from Newton's law of motion.
The body would be decelerating so,
V = u - gt
Where u is initial velocity and v is final velocity. g is acceleration of free fall due to gravity.
Hence,
V-U/ -g = t
Hence 25cos30 - 25/ -9.8 = 0.34s.
2.Now the length of the jump is defined as the total horizontal distance which is marked off by the horizontal velocity and time taken for take off and landing.
Hence Distance,S = u × t
25 ×0.34 =8.5m.
3. The maximum height is defined that at that point the Final velocity is 0m/s
Now the initial velocity is 25m/s
From Newton's law that;
V2= U2 -2gH; where U and V are initial and final velocity and H is height.
Hence H = V2-U2/-2g
=(0)^2- (25)^2/ -2×9.8
= -625/-19.6 =31.89m
Answer:
Explanation:
As we know that
here we have
also we know
so we have
so the height above window is given as
Answer:
a) the acceleration is -9.8 m/s^2 (gravity's acceleration), the magnitude is 9.8 m/s^2 and the direction is downwards.
The pebble is not decelerating since the magnitude of it's speed is increasing, even if it is on a negative direction.
b) after 0.5 s the pebble is 5.725 meters down. (or -5.725m from it's initial position.)
Explanation:
a) the acceleration is given only by gravity, it's the only force acting on the pebble, the slingshot only gives the pebble an initial speed.
b) To calculate the position we use the equation
y0 + v0·t + ½·g·t² = yf
replacing:
0 + (-9.0m/s) * 0.5s + 1/2 (-9.8)*0.5² = yf
-5.725 = yf
