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3 years ago

A train travels 55 kilometers in 2 hours, and then 52 kilometers in 5 hours. What is its average speed?

Physics

2 answers:

Dafna11 [192]3 years ago

6 0

Average speed = (total distance covered) / (time to cover the distance) .

Total distance covered = (55 km + 52 km) = 107 km

Time to cover the distance = (2 hrs + 5 hrs) = 7 hrs

Average speed = (107 km) / (7 hrs)

Average speed = 15.29 km/hour

bulgar [2K]3 years ago

4 0

The formula for working out speed is distance ÷ time.

55 km ÷ 2 hours = 27.5 km/h (average speed for first part of journey)

52km ÷ 5 hours = 10.4 km/h (average speed for second part of journey)

(27.5 + 10.4) ÷ 2 = 18.95 km/h (average speed throughout the journey)

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3 years ago

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iren2701 [21]

1) The electric potential at a distance r from a single point charge is given by
$V(r) = k \frac{q}{r}$
where k is the Coulomb's constant, q is the charge and r is the distance from the charge.

The charge in this problem is
$q=2.2 \mu C =2.2 \cdot 10^{-6} C$
So the potential at distance $r=6.3 m$ is
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2) By using the same formula as before, we can find the electric potential at distance r=99 m from the charge:
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