10 public questions tagged with this topic.
Centripetal acceleration a_c=v²/r=4π²r/T²=4π²rf² per NCERT circular motion. Substituting r and frequency/period gives a_c value matching 27 m/s. Other options use incorrect r or f, so C is correct.
Ref: NCERT Class 11 Physics > Chapter 4: Motion in a Plane > Topic: Motion in a Plane and Projectile Motion
Vertical velocity: vy=2gh=2×9.8×44.1=863.28≈29.38m/s. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 25 m/s as the result, so option A is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Acceleration and Velocity Analysis - Part 8
For free fall, s=½gt² and v²=2gh per NCERT. With g=10 m/s², given height or velocity yields time or distance via these equations. Substituting values gives result matching 25 m/s. This confirms option A as correct by uniformly accelerated motion equations.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Acceleration and Velocity Analysis - Part 8
Convert speed: 108km/h=108⋅10003600=30m/s. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 30 m/s as the result, so option A is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Distance, Displacement and Velocity-Time Relations
Use v2=v02+2ax. Here, v0=0, v=24m/s, x=72m. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 3 m/s² as the result, so option C is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Free Fall and Vertical Motion
Convert speed: 36km/h=36⋅10003600=10m/s. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 18 km as the result, so option A is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Free Fall and Vertical Motion
Use a=v−v0t. Here, v=30m/s, v0=10m/s, t=5s. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 4 m/s² as the result, so option A is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Free Fall and Vertical Motion
For constant speed, distance x=vt. As per NCERT Chapter 3, equations v=u+at, s=ut+½at², v²=u²+2as describe uniformly accelerated motion. Applying correct signs and units gives 200 m as the result, so option A is correct.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Free Fall and Vertical Motion
For free fall, s=½gt² and v²=2gh per NCERT. With g=10 m/s², given height or velocity yields time or distance via these equations. Substituting values gives result matching 1.5 s. This confirms option A as correct by uniformly accelerated motion equations.
Ref: NCERT Class 11 Physics > Chapter 3: Motion in a Straight Line > Topic: Kinematic Equations and Uniformly Accelerated Motion
Mechanistic model of myosin step size explains velocity differences among isoforms. Lever arm hypothesis states small conformational change of converter domain upon phosphate release rotation about 10 degrees amplified by rigid lever arm helical neck decorated with IQ motifs bound to light chains acting as fulcrum. Step size roughly equals lever length times angular change, so each IQ motif about 5 to 6 nanometer contributes. Constructing chimeras fusing artificial alpha actinin repeats or duplicating IQ motifs increased sliding speed linearly in motility assays without altering ATPase kcat, confirming length determines speed. Myosin V with six IQ motifs long lever moves 36 nanometer step fast cargo transport, myosin II with two IQ short lever 5 to 10 nanometer slower but ensemble force generation. Regulatory light chain phosphorylation changes recruitment and duty ratio in smooth muscle, actin length affects number of interacting heads not intrinsic speed, ATP concentration alters velocity only below Km about 50 micromolar. Therefore intrinsic determinant of maximal speed at saturating ATP is length of lever arm translating small catalytic domain rotation into amplified translation and faster sliding.
Ref: Alberts et al., Molecular Biology of the Cell, 7th ed., Chapter 16: Lever Arm Length and Myosin Speed.
