Question

motion at constant speed
chapter problems
homework

1. a polar bear walks a distance of 160 meters in 60 seconds. what was its speed?
2. a train travels 120 seconds at a speed of 50 m/s. how far did it go?
3. how long will it take a runner to travel a distance of 1000 m at a speed of 12 m/s?
4. a sailboat travels a distance of 600 m in 40 seconds. what speed is it going?
5. what distance will a car travelling at a speed of 15 m/s cover in 300 s?
6. how long will it take a ball to roll 10 meters along the floor at a speed of 0.5 m/s?

Explanation:

Problem 7

Step1: Recall speed formula

Speed \( v = \frac{d}{t} \), where \( d \) is distance, \( t \) is time.

Step2: Substitute values

\( d = 160 \, \text{m} \), \( t = 60 \, \text{s} \), so \( v = \frac{160}{60} \approx 2.67 \, \text{m/s} \).

Step1: Recall distance formula

Distance \( d = v \times t \), where \( v \) is speed, \( t \) is time.

Step2: Substitute values

\( v = 50 \, \text{m/s} \), \( t = 120 \, \text{s} \), so \( d = 50 \times 120 = 6000 \, \text{m} \).

Step1: Recall time formula

Time \( t = \frac{d}{v} \), where \( d \) is distance, \( v \) is speed.

Step2: Substitute values

\( d = 1000 \, \text{m} \), \( v = 12 \, \text{m/s} \), so \( t = \frac{1000}{12} \approx 83.33 \, \text{s} \).

Answer:

\( \approx 2.67 \, \text{m/s} \)

Problem 8