Straight
You already have to momentum of walking forward, and going back and forth are the same distance. If you go back then you would have to stop, turn and walk, but if you go forward you just have to walk.
Answer:
Mg will replace Ag in a compound
Explanation:
A single replacement reaction is driven by the position of ions on the activity series.
As a rule of thumb, the position of metal ions on the activity series determines their reactivity.
Metal ions that are above another are more reactive and they will displace those that are lower.
Generally, activity increases as we go up the group.
Mg ions are higher than Ag ions on the series so, Mg will displace Ag from a solution.
It is salt water because they are two things combined together.
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...
