Answer: 24.7 km/h

Explanation:

1) Average speed definition and formula

The average speed is the total distance run divided by the time elapsed:

S = distance / time

2) Distance 1 = 67 km

3) Distance 2 = 81 km

4) Total distance traveled = 67 km + 81 km = 148 km

5) time 1 = 1 hour

6) time 2 = 5 hours

7) total time = time 1 + time 2 = 1 h + 5 h = 6 h

8) Average speed:

S = 148 km / 6 h = 24.7 km/h

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2 years ago

A 0.050 kg bullet strikes a 5.0 kg wooden block with a velocity of 909 m/s and embeds itself in the block which fies off its sta

serg [7]

Answer:

The final velocity of the bullet is 9 m/s.

Explanation:

We have,

Mass of a bullet is, m = 0.05 kg

Mass of wooden block is, M = 5 kg

Initial speed of bullet, v = 909 m/s

The bullet embeds itself in the block which flies off its stand. Let V is the final velocity of the bullet. The this case, momentum of the system remains conserved. So,

$mv=(m+M)V\\\\V=\dfrac{mv}{m+M}\\\\V=\dfrac{0.05\times 909}{0.050+5}\\\\V=9\ m/s$