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An object of mass 6 kg accelerates from 5 m/s to 9 m/s in 8 s. How much work was done on the object during this time? how much power was applied? what is its change in momentum?

User Colim
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1 Answer

7 votes

Answer:

(1)540 J

(2)67.5 J/s or 67.5W

(3)look at underline statement in explanation

Step-by-step explanation:

(1) acceleration = change in speed ÷ time

= (9-5)m/s ÷ 8s

= 0.50 m/s²

resultant force of object during motion

= mass(in kg) × acceleration

= 6 × 0.50 = 3 N

displacement of force applied

= area under speed time graph(when sketched out, it's a trapezium)

= ½ × (5+9) × 8

= 180m

work done is measured in joules

= force × displacement of force applied

= 3N × 180m

= 540 J

detailed explanation:

altho the final unit for the work done should be Nm, but J is equal to Nm.

(2) Power is measured by J/s

therefore power = 540 J ÷ 8s = 67.5 J/s or 67.5 W

(3) the object accelerates constantly along a straight road

User Kyle Parsons
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