Answer:
(Example Person) has to push hard to get the skateboard started, but once it begins moving, it takes much less effort to keep it rolling over the smooth, flat pavement. In fact, if (Example Person) tries to stop the rolling skateboard, it may take as much effort to stop it as it did to start it rolling in the first place.
Explanation:
Hope this helps :)
Answer:
I think it's A but I'm not sure
Answer:
The sun is the ultimate source of energy for all food chains. Through the process of photosynthesis, plants use light energy from the sun to make food energy. Energy flows, or is transferred through the system as one organism consumes another.
Explanation:
W = PE
W = mgh
1500 J = (20 kg) (9.8 m/s²) h
h = 7.65 m
Round as needed.
Answer:
(a) 152.85 Nm
(b) 1528.5 Nm
Explanation:
According to the formula of power
P = τ ω
ω = 2 π f
(a) f = 2500 rpm = 2500 / 60 = 41.67 rps
So, 40 x 1000 = τ x 2 x 3.14 x 41.67
τ = 152.85 Nm
(b) f = 250 rpm = 250 / 60 = 4.167 rps
So, 40 x 1000 = τ x 2 x 3.14 x 4.167
τ = 1528.5 Nm
