Answer:
There is an interval of 24.28s in which the rocket is above the ground.
Explanation:
From Kinematics, the position 
as a function of time when the engine still works will be:
At what time the altitud will be ?
⇒ 
Using the quadratic formula: 
.
How much time does it take for the rocket to touch the ground? No the function of position is:
Where our new initial position is 
, the velocity when the engine breaks is 
and the only acceleration comes from gravity (which points down).
Now, when the rocket tounches the ground:
Again, using the quadratic ecuation:
Now, the total time from the moment it takes off and the moment it tounches the ground will be:
.
Answer:
OC. blizzard
Explanation:
In the United States, the National Weather Service defines a blizzard as a severe snow storm characterized by strong winds causing blowing snow that results in low visibilities. ... A severe blizzard has winds over 72 km/h (45 mph), near zero visibility, and temperatures of −12 °C (10 °F) or lower.
Answer:
Tension maximum =1131.9 N
Tension minimum =868.28 N
Tension at 3/4= 1065.995 N
Explanation:
a)
Given Mass of wrecking ball M1=88.6 Kg
Mass of the chain M2=26.9 Kg
Maximum Tension Tension max=(M1+M2) × (9.8 m/s²)
=(88.6+26.9) × (9.8 m/s²)
=115.5 × 9.8 m/s²
Tension maximum =1131.9 N
b)
Minimum Tension Tension minimum=Mass of the wrecking ball only × 9.8 m/s²
=88.6 × 9.8 m/s²
Tension minimum =868.28 N
c)
Tension at 3/4 from the bottom of the chain =In this part you have to use 75% of the chain so you have to take 3/4 of 26.9
= (3/4 × 26.9)+88.9) × 9.8 m/s²
= (20.175+88.6) × 9.8 m/s²
=(108.775) × 9.8 m/s²
=1065.995 N
Answer:
B.)Angular momentum is always conserved
Explanation:
Angular momentum is given by:
where
m is the mass of the object
v is its speed
r is the distance between the object and the centre of its circular trajectory
In absence of external torques, angular momentum is always conserved. That means that for the spinning star, if its radius r decreases (because it shrinks), in order for L (the angular momentum) to be conserved, the speed (v) must increases, therefore the spinning star speeds up.
So, the correct choice is
B.)Angular momentum is always conserved
C. in a liquid, the partivles are compact and move a bit slower than gas
