Fig. 1.1 shows a car of mass 1000 kg that speeds up from rest to 10 m/s in 5 s on a level road. Ignoring friction, what average power gives it this kinetic ...

Assessment: Physics 0625 | Paper 1 Mock 01 | Multiple Choice (Core) Subject: Physics - 0625

Question 1 Report

Fig. 1.1 shows a car of mass 1000 kg that speeds up from rest to 10 m/s in 5 s on a level road. Ignoring friction, what average power gives it this kinetic energy?

diagram

Answer Details

The correct answer is 10 000 W. First find the kinetic energy gained: \( KE = \tfrac{1}{2}mv^{2} = \tfrac{1}{2} \times 1000 \times 10^{2} = 50\,000 \) J. Then average power is \( P = \frac{E}{t} = \frac{50\,000}{5} = 10\,000 \) W. Choosing 50 000 W forgets to divide by time; 2000 W uses \( mv/t \) without the half; 5000 W halves the correct answer again.

Download The App On Google Playstore

Everything you need to excel in your exams

Green Bridge CBT Mobile App
Personalized AI Learning Chat Assistant
200,000+ Exam Questions Across IGCSE, JAMB, WAEC & NECO
Over 3,900 Lesson Notes
Offline Support - Learn Anytime, Anywhere
Green Bridge Timetable
Literature Summaries & Potential Questions
Track Your Performance & Progress
In-depth Explanations for Comprehensive Learning