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During the ride, pillion rider and driver are in a state of motion. But when the driver applies brakes, the body of pillion rider continues moving forward on account of inertia of motion. Therefore, the pillion rider falls forward.
It states that the sum of momenta of the two objects before collision is equal to the sum of momenta after the collision, provided there is no external unbalanced force on them. In other words, the initial momentum of the two objects is unchanged or conserved.
Apical Meristem:
It is present at the root apex and the shoot apex. The shoot apical meristem is present at the tip of the shoots and its active division results in the elongation of the stem and formation of new leaves. The root apical meristem helps in root elongation.
As the man jumps out from a moving train, his feet suddenly come to rest on touching the ground while his body’s upper part continues to move forward. For this reason he falls with his head forward. So as to save himself, he should run through some distance in the forward direction.
Newton’s law of motion. Newton’s three laws may be stated as follows :
First Law. A body at rest or in uniform motion will remain at rest or in uniform motion unless an unbalanaced force acts upon it.
Second Law. The rate of change of momentum of a body is directly proportional to the applied unbalanced force and the change takes place in the direction of the force.
Third Law. Action and reaction are equal and opposite and they act on different bodies.
Phycomycetes- This group of fungi includes members such as Rhizopus, Albugo, etc.
(i) Mode of nutrition
They are obligate parasites on plants or are found on decaying matter such as wood.
(ii) Mode of reproduction
Asexual reproduction takes place through motile zoospores or non6motile aplanospores that are produced endogenously in sporangium. Sexual reproduction may be of isogamous, anisogamous, or oogamous type. It results in the formation of thick6walled zygospore.
The force of friction is directly proportional to the weight of the body sliding over the surface. The force of friction also depends on the nature of the surfaces in contact.
Ans. Friction is a very important force in our daily life. Some advantages of friction are :
(1) It is due to the friction between the road and the soles of our shoes that we are able to walk.
(2) The nails and screws hold the wooden boards together due to friction.
(3) The friction between the road and the surface of the tyre permits safe driving.
(4) The application of brakes to stop a scooter or car etc. is possible only due to friction.
Answer:
The main function of the leaves is to carry out the process of photosynthesis. However, in a few plants, leaves are modified to perform different functions.
(a) Tendrils: The leaves of a pea plant are modified into tendrils that help the plant in climbing.
(b) Spines: The leaves in cactus are modified into sharp spines that act as an organ of defense.
(c) Phyllode: The leaves of some Australian acacia are short-lived and soon replaced by flattened, green structures called phyllodes that arise from the petiole of the leaves. The petioles in these plants synthesize food.
(d) Pitcher: The leaves of the pitcher plant are modified into pitcher-like structures, which contain digestive juices and help in trapping and digesting insects.
