Question

1.первую треть пути муравей прополз со скоростью 20см/с, потом одну секунду про стоял неподвижно ,затем двигался со скоростью 30 см/с.Средняя скорость движения за все время пути оказалась равна 20м/с.Найти время путешествия муравья

Answer 1

S=S1+S2
S=Vср*(t+tc)
S/20=t+tc    (1)
S/3*V1+2*S/3*V2=t
S(1/3*V1+2/3*V2)=t
S(1/60+2/90)=t
S(3/180+4/180)=t
S*7/180=t  (2)
поделим 2 на 1
20*7/180=1+tc/t
tc/t=1-7/9=2/9
t=9*tc/2=4,5 мин

Answer 2

Calculation of Ant's Travel Time

To find the total travel time of the ant, we need to calculate the time it took for each segment of its journey and then sum them up.

Given information: - The ant traveled the first third of the distance at a speed of 20 cm/s. - It then stood still for one second. - Finally, it traveled the remaining distance at a speed of 30 cm/s. - The average speed for the entire journey is 20 m/s.

Let's calculate the time for each segment and then sum them up to find the total travel time.

1. Time for the first segment: - Distance: 1/3 of the total distance - Speed: 20 cm/s - Time = Distance / Speed = (1/3) * Total Distance / 20 cm/s

2. Time for the second segment: - The ant stood still for 1 second, so the time for this segment is 1 second.

3. Time for the third segment: - Distance: 2/3 of the total distance (remaining distance) - Speed: 30 cm/s - Time = Distance / Speed = (2/3) * Total Distance / 30 cm/s

Now, let's calculate the total travel time by summing up the times for each segment.

Total Travel Time = Time for the first segment + Time for the second segment + Time for the third segment

Note: We need to convert the units to ensure consistency. The given average speed is in m/s, so we need to convert the distances to meters.

Let's perform the calculations:

1. Time for the first segment: - Distance: (1/3) * Total Distance (in meters) - Speed: 20 cm/s = 0.2 m/s - Time = Distance / Speed = (1/3) * Total Distance / 0.2 m/s

2. Time for the second segment: - Time = 1 second

3. Time for the third segment: - Distance: (2/3) * Total Distance (in meters) - Speed: 30 cm/s = 0.3 m/s - Time = Distance / Speed = (2/3) * Total Distance / 0.3 m/s

Total Travel Time = Time for the first segment + Time for the second segment + Time for the third segment

Now, let's calculate the total travel time using the given information.

Please note that the given information is incomplete and does not provide the total distance. Without the total distance, we cannot calculate the exact travel time.

If you provide the total distance, I can help you calculate the travel time.