Answer:
Newton's first law, an object will stay at rest only if there are no external forces acting on the object or if the net external force acting on the object is zero. Since the barbell is at rest (not moving), the net external force acting on it must be zero
Newton's Second Law of Motion via the equation f = ma, or put differently, force is equal to mass multiplied by acceleration. To generate more force, we must either increase mass or acceleration (or both)
Newton's Third Law of Motion is known as the equal and opposite reaction principle
The angular speed of the merry-go-round is
ω = 0.10 rad/s
The angular moment of inertia of a mass, m, at a radius, r, from the center of the wheel is
I = mr²
Therefore, the angular moment of inertia for the children are
I₁ = (25 kg)*(1.0 m)² = 25 kg-m²
I₂ = (25 kg)*(1.5 m)² = 56.25 kg-m²
The combined angular momentum is
ω(I₁ + I₂) = (0.10 rad/s)*(25 + 56.25 kg-m²)
= 8.125 (kg-m²)/s
Answer: 8.125 (kg-m²)/s
a) gia tốc = vf-vi / t
a = 14-10 / 20
a = 0,2ms⁻²
b) dưới dạng a = Δv / t
v = lúc
v = 0,2 × 40
v = 8ms⁻¹
như v = d / t
do đó d = vt
d = 8 × 40
d = 320m
hãy đánh dấu là trí óc nhất