When a body falls freely under gravity, its MCQ with Answer and Explanation
Question
Report Error
Discuss this Question (0)
Practice More Physics Questions
Question #1
Report Error
A machine gun fires 60 bullets per minute, each of mass 10 g with velocity 600 m/s. The power developed by the gun is:
Correct Answer: Option B
Explanation:
Power = work done per unit time = kinetic energy imparted per second. KE per bullet = ½mv² = ½×0.01×(600)² = 1800 J. Bullets per second = 60/60 = 1. Thus power = 1800 J/s = 1800 W. Note: Mass conversion: 10 g = 0.01 kg. This problem combines kinetic energy formula with power definition. Exam tip: Always convert to SI units first (grams to kg, minutes to seconds). Such numerical problems test multi-step calculation skills and unit conversion proficiency essential for competitive examinations.
Power = work done per unit time = kinetic energy imparted per second. KE per bullet = ½mv² = ½×0.01×(600)² = 1800 J. Bullets per second = 60/60 = 1. Thus power = 1800 J/s = 1800 W. Note: Mass conversion: 10 g = 0.01 kg. This problem combines kinetic energy formula with power definition. Exam tip: Always convert to SI units first (grams to kg, minutes to seconds). Such numerical problems test multi-step calculation skills and unit conversion proficiency essential for competitive examinations.
Question #2
Report Error
A body moves with uniform acceleration. The graph between velocity and time is:
Correct Answer: Option A
Explanation:
Uniform acceleration means constant rate of change of velocity: a = dv/dt = constant. Thus v = u + at, a linear equation in t. Graph is straight line with slope = acceleration. Parallel to time axis (A) implies zero acceleration (constant velocity). Parabola (C) is for position-time under constant acceleration. Memory tip: 'v-t graph slope = acceleration; area = displacement'. This graph interpretation question tests kinematics fundamentals, frequently examined in competitive exams. Always link graph features to physical quantities: slope, area, intercepts have specific meanings in motion graphs.
Uniform acceleration means constant rate of change of velocity: a = dv/dt = constant. Thus v = u + at, a linear equation in t. Graph is straight line with slope = acceleration. Parallel to time axis (A) implies zero acceleration (constant velocity). Parabola (C) is for position-time under constant acceleration. Memory tip: 'v-t graph slope = acceleration; area = displacement'. This graph interpretation question tests kinematics fundamentals, frequently examined in competitive exams. Always link graph features to physical quantities: slope, area, intercepts have specific meanings in motion graphs.
Question #3
Report Error
The part of the eye that controls the amount of light entering is
No comments yet. Be the first to start the discussion!