Answer:
Plants slow down water as it flows over the land and this allows much of the rain to soak into the ground. Plant roots hold the soil in position and prevent it from being blown or washed away. Plants break the impact of a raindrop before it hits the soil, reducing the soil's ability to erode.
Explanation:
103.9 hours, if you never stopped for any reason.
Answer:
112.5 N
Explanation:
50 = GMm/r^2
Let F be the new force of attraction
F/50 = ( G(3M)(3m)/(2r)^2 ) / (GMm/r^2)
[Elimiating G,M,m,r]
F = 112.5 N
Answer:
Burning Paper
Explanation:
This is a chemical reaction, because new substances are formed
Answer:
v = 10 m/s
Explanation:
Let's assume the wheel does not slip as it accelerates.
Energy theory is more straightforward than kinematics in my opinion.
Work done on the wheel
W = Fd = 45(12) = 540 J
Some is converted to potential energy
PE = mgh = 4(9.8)12sin30 = 235.2 J
As there is no friction mentioned, the remainder is kinetic energy
KE = 540 - 235.2 = 304.8 J
KE = ½mv² + ½Iω²
ω = v/R
KE = ½mv² + ½I(v/R)² = ½(m + I/R²)v²
v = √(2KE / (m + I/R²))
v = √(2(304.8) / (4 + 0.5/0.5²)) = √101.6
v = 10.07968...
