A body is thrown vertically upward with speed 40 m/s. Distance travelled in last second of ascent (g=10)
A. 35 m
B. 15 m
C. 20 m
D. 5 m
Answer: Option D
Solution (By JKExamLibrary)
Time of ascent = u/g = 4 s. Distance in last second (4th) = ½g(1)²? Actually, during last second of upward journey, velocity becomes zero. Distance = ½g(1)² = 5 m. Formula: s = u - g/2 (2n-1) with n=4? Let's compute: s_nth = u - (g/2)(2n-1). For n=4 (4th second), s = 40 - 5×7 = 40 - 35 = 5 m. Yes.
Explanation:
Convection involves bulk movement of fluid particles (liquid/gas). Conduction: vibration transfer without particle movement. Radiation: EM waves. Absorption is taking in heat.
Explanation:
Electrical energy (E) = Power (P) × Time (t). Power = 60 W = 0.06 kW. Time per day = 5 hours. Total time in 30 days = 5 × 30 = 150 hours. Energy = 0.06 kW × 150 h = 9 kWh (or 9 units of electricity). One kWh is the commercial unit of energy.
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