A body with initial speed 7 m/s accelerates uniformly at 5 m/s² over 48 m. What is its final speed?
Answer and explanation
Correct answer: A. 23 m/s
- Step 1: Use v² = u² + 2as. Step 2. v² = 49 + 2 × 5 × 48 = 529, so v = 23 m/s. Answer: 23 m/s. Why not the others: 529 m/s is what you get if you forget the square root. 247 m/s is what you get if you use v = u + as. 25 m/s is what you get if you subtract 2as.
Practise more Physics and chemistry.
Free questions with an explanation for every one, and full timed DTM University Entrance Test (Uzbekistan) mock tests.
More Physics and chemistry questions
- Which unit is used for force in the SI system?
- A car moving at 20 m/s accelerates at 2 m/s² for 5 s. What is its final speed?
- A resistor of 6 Ω carries a current of 2 A. What is the voltage across it?
- What is the kinetic energy of a 2 kg object moving at 3 m/s?
- A stone falls from rest for 2 s. Taking g = 10 m/s², how far does it fall?
- Which part of the electromagnetic spectrum has the highest frequency?