Answer:
height = 45 m
Explanation:
Initial velocity = 0 m/s
Final velocity = 30 m/s
Acceleration due to gravity = +10m/s^2 ( because ball is going down )
Using the eqn of motion
where v= final velocity ; u = initial velocity ; g = acceleration due to gravity ; h = height
So,
The answer would be option D "a ball sitting on a shelf." Potential energy is the amount of energy a object has while it's at rest.. (or not moving) Kinetic energy is how much energy a object is while it's moving. So in this case it's option D because a ball sitting on a shelf isn't moving therefore it has potential energy. It's not option A because thats a example of kinetic energy since how the roller coaster is moving. It's not option B because it's kinetic energy because the bike is moving. It's also not option C because it's kinetic energy because the bird is moving.
Hope this helps!
Answer:
a) 19.4 m/s
b) 19 m/s
Explanation:
a) In the given question,
the potential energy at the initial point = Ui = 0
the potential energy at the final point = Uf = mgh
the kinetic energy at the initial point = Ki = 1/2 mv₀².
the kinetic energy at the final point = Kf = 0
work done by air= Ea= fh = 0.262 N
Now, using the law of conservation of energy
initial energy= final energy
Ki +Ui = Kf + Uf +Ea
1/2 mv₀² + 0 = 0 + mgh + fh
1/2 mv₀² = mgh + fh
h = v₀²/ 2g (1 +f/w)
calculate m
m= w/g = 5.29 /9.8
= 0.54 kg
h = 20 ²/ (2 x9.80) x (1 0.265/5.29)
h = 19.4 m.
b) 1/2 mv² + 2fh = 1/2 mv₀²
Vg = 19 m/s
Answer:
Explanation:
we humans have our own ify classification for celestial objects, most people are saddened that pluto is not a planet anymore altho it hasn't changed at all.
scientist say that if an object is going to be considered a planet it must fill in these three checkboxes:
You must be spherical, you must orbit a star, and you must have already cleared your path or debris.
Pluto fills in the first two boxes but it does orbit in the keyperbelt and there are 5 other objects just like it. this is why pluto has been dubbed a dwarf planet.
