Explanation:
Speed has only magnitude.
Velocity has magnitude and direction.
"A bike goes 25 m/s toward main street."
This includes a direction, so it is velocity (V).
"A person walks 4 mph."
This has only magnitude, so it is speed (S).
"A plane flies 200 m/s."
This has only magnitude, so it is speed (S).
"A bird flies 100 mph due south."
This includes a direction, so it is velocity (V).
In the real universe, no black holes contain singularities. In general, singularities are the non-physical mathematical result of a flawed physical theory.
Answer:
Josh is the strongest
The net force is 5N towards right
Explanation:
Draw a free body diagram for each disc.
Disc A has three forces acting on it: 86.5 N up, T₁ down, and Wa down.
∑F = ma
86.5 N − T₁ − Wa = 0
Wa = 86.5 N − T₁
ma × 9.8 m/s² = 86.5 N − 55.6 N
ma = 3.2 kg
Disc B has three forces acting on it: T₁ up, T₂ down, and Wb down.
∑F = ma
T₁ − T₂ − Wb = 0
Wb = T₁ − T₂
mb × 9.8 m/s² = 55.6 N − 36.5 N
mb = 1.9 kg
Disc C has three forces acting on it: T₂ up, T₃ down, and Wc down.
∑F = ma
T₂ − T₃ − Wc = 0
Wc = T₂ − T₃
mc × 9.8 m/s² = 36.5 N − 9.6 N
mc = 2.7 kg
Disc D has two forces acting on it: T₃ up and Wd down.
∑F = ma
T₃ − Wd = 0
Wd = T₃
md × 9.8 m/s² = 9.6 N
md = 0.98 kg