We use the kinematic equation: v² = u² +2as Substituting the values: 0 =(20)²+ 2a(200) 0 = 400 + 400a 400a = −400 a =−1 m/s² The negative sign indicates retardation. Thus, the retardation = 1 m/s². Class 9th Science ...
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Radius of circular track = 100 m Time for one complete lap = 62.8 s Calculating Average Speed: Speed = Total distance / Total time Total distance covered in one lap = Circumference of the circle = 2πR = 2 ...
The athlete completes one round of the circular track in 40 seconds. Total time given = 2 minutes 20 seconds = 140 seconds Number of rounds completed = 140 ÷ 40 = 3.5 rounds Class 9th Science NCERT MCQ Questions
(c) The total distance covered by Arun is 20 km, but his displacement is zero. Distance is the total length of the path traveled, so Arun covers 10 km to station B and 10 km back, totaling 20 km. However, ...
The correct answer is:(a) Suberin. Cork cells are made impervious to water and gases due to the presence of suberin, a hydrophobic substance that forms a protective barrier, preventing water loss and providing resistance to microbial attack. Class 9th Science ...
The correct answer is:(d) remain at the same position. Trees grow from their tips (both at the roots and shoots), not by stretching upwards from the base. So, the nail will stay at the same height, though it might get ...
The correct answer is:(b) Collenchyma. Commercial fibers like jute and flax are derived from the collenchyma tissue, which provides mechanical support and flexibility to plants. These fibers are obtained from the stem and are widely used in making ropes, bags ...
The correct answer is:(c) Companion cells Companion cells, which are found in the phloem of vascular plants, retain their nucleus at maturity. They play a crucial role in supporting sieve tube elements, which lose their nucleus at maturity but remain ...
The correct answer is:(d) Limbs. Voluntary muscles, also known as skeletal muscles, are found in the limbs and are under conscious control, allowing for movement of body parts. Class 9th Science NCERT MCQ Questions NCERT Books MCQ Questions Session 2024-2025.
The correct answer is:(d) striated, uninucleated, branched and involuntary. Cardiac muscles are striated (having a banded appearance), uninucleated (one nucleus per cell), branched (forming a network), and involuntary (their contraction is not under conscious control). They are found in the ...