Question

apply the formula for velocity, ( v = \frac{d}{t} ), to solve the five problems.
a car travels 10 miles east in 30 minutes.
sarah walks to school, 1.5 miles in 30 minutes.
the world record for the men’s marathon, 42 km, is 2 hours and 3 minutes.
miguel threw a baseball a distance of 40 meters. it hit the ground in 5 seconds.
a motorist travels 130 km in 2 hours.
velocity options: 8 m/s, 3 mi/h, 20 mi/h, 65 km/h, .35 km/min

Explanation:

1. A car travels 10 miles east in 30 minutes.

Step1: Identify d and t

d = 10 miles, t = 30 minutes.

Step2: Apply \( v=\frac{d}{t} \)

\( v=\frac{10}{30}=\frac{1}{3}\approx 0.333\) miles per minute? Wait, no, wait, 10 miles in 30 minutes. Wait, 30 minutes is 0.5 hours? No, wait, the answer options have 20 mi/h? Wait, no, 10 miles in 30 minutes. Let's convert minutes to hours: 30 minutes = 0.5 hours. Then \( v=\frac{10}{0.5}=20 \) mi/h. Oh right, because 30 minutes is 0.5 hours. So \( v = \frac{10 \text{ miles}}{0.5 \text{ hours}} = 20 \) mi/h.

Step1: Identify d and t

d = 1.5 miles, t = 30 minutes = 0.5 hours (or keep as 30 minutes for mi/min, but answer has 3 mi/h). Let's use hours: t = 0.5 h.

Step2: Apply \( v=\frac{d}{t} \)

\( v=\frac{1.5}{0.5}=3 \) mi/h.

Step1: Convert time to minutes or hours. 2 hours 3 minutes = 2 + 3/60 = 2.05 hours? Wait, no, 3 minutes is 3/60 = 0.05 hours, so total t = 2.05 h? Wait, no, the answer has 0.35 km/min? Let's convert time to minutes: 2 hours = 120 minutes, plus 3 minutes = 123 minutes. d = 42 km. Then \( v=\frac{42}{123}\approx 0.341 \approx 0.35 \) km/min.

Step2: Calculate velocity

\( v=\frac{42 \text{ km}}{123 \text{ min}}\approx 0.35 \) km/min.

Answer:

20 mi/h

2. Sarah walks to school, 1.5 miles in 30 minutes.