Answer:
B according to the picture
Explanation:
Star of 3 stellar masses => red supergiant=>supernova=>neutron star
Answer:
Average velocity of an object is equal to the instantaneous velocity when it's acceleration is zero.
Explanation:
We have the equation of motion 
, where s is the displacement, a is the acceleration, u is the initial velocity and t is the time taken.
Here s = 300 m, u = 0 m/s, a = 9.81 
Substituting
Now we have v = u+at, where v is the final velocity
Here u = 0 m/s, a= 9.81 and t = 7.82 seconds
Substituting
v = 0+9.8*7.82 = 76.68 m/s
The speed with which the penny strikes the ground = 76.68 m/s.
(a) At a corresponding hill on Earth and a lesser gravity on planet Epslion, the height of the hill will cause a reduction in the initial speed of the snowboarder from 4 m/s to a value greater than zero (0).
(b) If the initial speed at the bottom of the hill is 5 m/s, the final speed at the top of the hill be greater than 3 m/s.
<h3>
Conservation of mechanical energy</h3>
The effect of height and gravity on speed on the given planet Epislon is determined by applying the principle of conservation of mechanical energy as shown below;
ΔK.E = ΔP.E
¹/₂m(v²- u²) = mg(hi - hf)
¹/₂(v²- u²) = g(0 - hf)
v² - u² = -2ghf
v² = u² - 2ghf
where;
- v is the final velocity at upper level
- u is the initial velocity
- hf is final height
- g is acceleration due to gravity
when u² = 2gh, then v² = 0,
when gravity reduces, u² > 2gh, and v² > 0
Thus, at a corresponding hill on Earth and a lesser gravity on planet Epslion, the height of the hill will cause a reduction in the initial speed of the snowboarder from 4 m/s to a value greater than zero (0).
<h3>Final speed</h3>
v² = u² - 2ghf
where;
- u is the initial speed = 5 m/s
- g is acceleration due to gravity and its less than 9.8 m/s²
- v is final speed
- hf is equal height
Since g on Epislon is less than 9.8 m/s² of Earth;
5² - 2ghf > 3 m/s
Thus, if the initial speed at the bottom of the hill is 5 m/s, the final speed at the top of the hill be greater than 3 m/s.
Learn more about conservation of mechanical energy here: brainly.com/question/6852965
