Answer:
A
Explanation:
60 + 30 = 90
90 divided by 3 = 30
30 divided by 60 = 0.5
so your answer is 0.5 m/s
Ke = (1/2)mv²
m = 100kg, v = 10 km/s = 10*1000 = 10000m/s
Ke = (1/2)*100*10000
Ke = 500000 Joules
Sea scorpions or Eurypterids lived about 251.9 million years ago. They were formidable predators and hunters, but they were wiped out in the Great Permian Mass Extinction, which is also known as the Great Dying (96% of all species on Earth went extinct).The largest species like Jaekelopterus was over 7 feet long! They were mainly thought to go extinct because of a slew of natural disasters that occurred when a comet hit the Earth, as well as increased volcanic activity polluting the seas that Sea scorpions lived in, as well as rising sea temperatures. The Silurian, when these Sea scorpions proliferated was when the water was cooler, holding in more nutrients, allowing both Sea Scorpions and other animals to spread all over the world. But as the oceans became polluted from the volcanoes (and the ash they produced) and the global ocean temperatures began to rise, many animals may not have been able to cope or adapt to the extreme change, becoming helpless in their nutrient deficient water (compared to what they were used to).
I hope this helps!
Question:<em> </em><em>Find, separately, them mass of the balloon and the basket (incidentally, most of the balloon's mass is air)</em>
Answer:
The mass of the balloon is 2295 kg, and the mass of the basket is 301 kg.
Explanation:
Let us call the mass of the balloon 
and the mass of the basket 
, then according to newton's second law:
,
where 
is the upward acceleration, and 
is the net propelling force (counts the gravitational force).
Also, the tension 
in the rope is 79.8 N more than the basket's weight; therefore,
and this tension must equal
Combining equations (2) and (3) we get:
since , we have
Putting this into equation (1) and substituting the numerical values of 
and 
, we get:
Thus, the mass of the balloon and the basket is 2295 kg and 301 kg respectively.
Answer:
Explanation:
a )
Time to reach the speed of 20 m/s with an acceleration of 2 m/s² can be calculated as follows .
v = u + a t
20 = 0 + 2 t
t = 20 /2 = 10 s .
Total time = 10 s + 20 s + 5 s = 35 s .
b) Average velocity = Total distance travelled / total time
Distance travelled in first 10 s
S₁ = ut + 1/2 a t²
= 0 + .5 x 2 x 10²
= 100 m
Distance travelled in next 20 s
S₂= 20s x 20 m/s = 400 m
Distance travelled in last 5 s .
deceleration in last 5 s
v = u + at
0 = 20 m/s + a x 5
a = - 4 m/s²
v² = u² - 2 a s
0 = (20 m/s)² - 2 x 4 m/s² x s
s = 50 m
S₃ = 50 m
Total distance = S₁ + S₂ + S₃
= 100 m + 400 m + 50 m
= 550 m .
Average velocity = 550 m / 35 s
= 15.71 m /s .
