PLEASE ANSWER THE QUESTIONS IN THE ATTACHMENT :
Answers
Answer:
q1) Equilibrium
q2) since earth act as a magnet
q3) centripetal force will be reduced
q4) if he takes the bucket parallel to to earth the work done =0
q5) since Pressure =Force /Area
Force =Pressure ×Area
q6) due to evaporation of sweat
q7) Humidity, Wind Speed.
q8) due to transfer of heat to surroundings
q9) g= acceleration due to gravity of earth [9.8i
G= Universal Gravitational constant
q10) To reduce Viscous Drag
q11) No
q12) Yes, friction is necessary but not at all
q13) Tou = mass
Explanation:
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1. Pencil balanced at its tip with centre of gravity G at the highest position will be left, the pencil will topple over weight acting at G about its tip and fall down. This is called the unstable equilibrium.
2. A gravitational field is a model used to explain the influence that a massive body extends into the space around itself producing a force on another massive body.. In its original concept, gravity was a force between point masses.
3. If the velocity is halved then centripetal force decreases by 4 times.
4. Work done by the force of gravity on the object is zero. Force of gravity acts in the vertical downward direction and the distance covered the of force, the horizontal direction. As there is no displacement in th hence the work done is zero.
5. The force is proportional to the area, for if we increase the area but keep the number of molecules per cubic centimeter the same, we increase the number of collisions with the piston in the same proportion as the area was increased.
more area = more space = more free for molecules = less pressure = less force
6. The sweat leaves your skin through tiny holes called pores. When the sweat hits the air, the air makes it evaporate. As the sweat evaporates off your skin, you cool down.
7. The rate of evaporation depends on the liquid's exposed surface area , the humidity of surroundings and the temperature.
8. The hot tea is at a higher temperature than the surroundings. The heat flows from hot objects to cold objects.The nearby air molecules will collide with the tea in the cup and take away its heat.
9. The constant of proportionality, G, is the gravitational constant.(g) ,which is the local gravitational field of Earth .
10. Vehicles are made wide to lower their center of gravity this helps in handling and makes it harder to roll the vehicles over in an accident.
11. If a body is moving with constant speed in a circle, then yes, that body has acceleration.
12. Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil.
13. Frictional force causes a lot of losses in general upkeep and wear and tear of machinery. Hence it is considered as a evil.
14. The position of the centre of gravity of an object affects its stability. The lower the centre of gravity (G) is, the more stable the object. The higher it is the more likely the object is to topple over if it is pushed.
15. A gravitational field is the force field that exists in the space around every mass or group of masses. This field extends out in all directions, but the magnitude of the gravitational force decreases as the distance from the object increases.
16. A small child has less force than a fat one. So , the distance from the pivot of the seesaw should be increased for the small child so that the moment of force or torque is increased. Hence distances have to be adjusted so that sum of clockwise moments matches the sum of anti clockwise moments.
17. Water is used as a coolant in automobiles radiators because it has high specific heat capacity. So, it absorbs a large amount of heat for a degree rise in temperature.
18. The magnitude of upthrust on a body due to a liquid depends on: Volume of the body submerged in the liquid . Density of the liquid in which the body is submerged.
19. The force of attraction is equal to the weight of the object. So, an apple weighing 1N attracts the Earth with 1N force.
20. The center of gravity of an object is the point one can use as the place where gravity pulls on the object.