Homework problems: Chapter 2 1. A walker covers 1.8 km in a time of 30 minutes.

Question

Homework problems: Chapter 2 1. A walker covers 1.8 km in a time of 30 minutes. What's his average speed in m/s? 2. A car ran at a speed of 20 m/s for 10 minutes. What's the distance it traveled? 3. A train achieves a velocity of 30 m/s from rest in 2 seconds. What's its acceleration? 4. A car travels with an initial velocity of 12 m/s and acceleration of 2.5 m/s2 for a time of 2 seconds. a) What's its speed at the end of this time? b) What distance does it travel during this time? 5. A car is moving at velocity Vo-30 m/s. It starts to slow down with an acceleration -2m/s. a) How long will it take to stop? b) What distance does it travel during this time?

Explanation / Answer

1. d = 1.8 km = 1800 m

t = 30 min = 1800 s

v = d/t = 1 m/s

2. v = 20 m/s

t = 10 min = 600 s

d = vt = 12000 m or 12 km

3. vf = vi + a t

30 = 0 + 2 a

a = 15 m/s^2

4. (A) v = vi + a t = 12 + (2.5 x 2)

v = 17 m/s

(B) d = vi t + a t^2 / 2

d= (12 x 2) + (2.5 x 2^2 / 2)

d = 29 m

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.