newton's second law

Question

A force of 20 N acts on a body of mass 4 kg initially at rest. What will be its velocity after 5 seconds?

RankGuru · Accepted Answer

1. **Newton's Second Law**: $F = ma$.
2. **Find Acceleration ($a$)**:
   - $a = F / m = 20 	ext{ N} / 4 	ext{ kg} = 5$ m/s$^2$.
3. **Kinematic Equation**: Use $v = u + at$.
4. **Substitution**:
   - Initial velocity $u = 0$ (at rest).
   - Acceleration $a = 5$ m/s$^2$.
   - Time $t = 5$ s.
5. **Calculation**: $v = 0 + (5 	imes 5) = 25$ m/s.

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newton's second law

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