A bus covers 10 km in 7 minutes. Find the speed of the bus in km/h
1 answer:
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- P_1=+3D
- P_2=-2D
Now
Answer:
a) 1.89 m/s b) 172.1 N
Explanation:
a)
- Applying the work-energy theorem, if we can neglect the friction between truck and road, the total change in kinetic energy must be equal to the work done by the external forces.
- This work, is just 4,475 J.
- So we can write the following equation:
- where m= mass of the truck = 2.5*10³ kg.
- So, we can find the speed v, as follows:
b)
- The work done by the man, is just the horizontal force applied, times the displacement produced by the force horizontally:
- We can solve for F, as follows: