It's basically asking for the acceleration. When an object is in free fall, the acceleration is just gravity. so in this case ∆v = 2.45 because it is the gravity on that planet.
Answer:
25.71 kgm/s
Explanation:
Let K₁ and K₂ be the initial and final kinetic energies of object A and v₁ and v₂ its initial and final speeds.
Given that K₂ = 0.7K₁
1/2mv₂² = 0.7(1/2mv₁²)
v₂ = √0.7v₁ = √0.7 × 20 m/s = ±16.73 m/s
Since A rebounds, its velocity = -16.73 m/s and its momentum change, p₂ = mΔv = m(v₂ - v₁) = 0.7 kg (-16.73 - 20) m/s = 0.7( -36.73) = -25.71 kgm/s.
Th magnitude of object A's momentum change is thus 25.71 kgm/s
1575 N
Explanation:
Step 1:
Let us consider that 350 J of energy is spent by that person to push a couch to 4.5 m from its initial position.
Let F be the force required and E be the energy spent and D be the distance traveled by the couch from its initial state.
In Physics, Work done = Force / Displaced distance
Step 2:
Let the work done be 350 J and Distance be 4.5 m
Then Force exerted = 
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