# A sled weighing 25 kg, moving uphill, reduced its speed from 7.2 km / h to 3.6 km / h.

June 30, 2021 | education

| **A sled weighing 25 kg, moving uphill, reduced its speed from 7.2 km / h to 3.6 km / h. What is the change in the sled’s momentum?**

Initial data: m (sled weight) = 25 kg; V (initial speed of the sleigh) = 7.2 km / h; V1 (final speed of the sled) = 3.6 km / h.

SI system: V = 7.2 km / h = 7.2 / 3.6 m / s = 2 m / s; V1 = 3.6 / 3.6 m / s = 1 m / s.

The change in the momentum of the sleigh can be calculated by the formula: ΔP = m * V1 – m * V = m * (V1 – V).

Let’s calculate: ΔP = 25 * (1 – 2) = -25 kg * m / s.

Answer: The change in the momentum of the sleigh is -25 kg * m / s.

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