Very Short Answer Type Questions
1. What are the different branches of mechanics?
2. What is kinematics?
3. How do you represent a vector geometrically?
4. What does the length of the line in geometrical rep-
resentation of a vector signify?
5. A body is first displaced by 5 m and then by
12 in different directions. The minimum
displacement it can have is
6. Motion and rest are relative. How do you justify this?
7. You are walking towards India Gate. Is India Gate at
rest with respect to you or in motion with respect to
19. Convert the following speeds into m s-1.
(a) 18 km h-1
(b) 63 km h-1
(c) 99 km h-1
(d) 108 km h-1
20. Convert the following speeds into km h-1.
(a) 2 m s-1
(b) 10 m s-1
(c) 12.5 m s-1
(d) 15 m s-1
21. 1 m -2 = km h-2
m
ו
m.
you?
22. A car attains a velocity of 20 m s-1 in 2.5 s. If initially
it had been at rest, its acceleration must be
23. What is the acceleration of a particle moving with
uniform velocity?
24. Rate of decrease in the magnitude of velocity is also
known as
25. The displacement-time graph of a body is shown in
the figure below. The part of the graph that repre-
sents the uniform motion of the body is
A
B
8. A passenger, seated in a train is at rest with reference
to
9. Define scalar quantities and vector quantities. Give
some examples.
10. The average value of acceleration due to gravity at
sea level is
m s-2
A
В
S
11. A particle moved 5 m towards east and then moved
8 m towards west. What is the total distance travelled
and the magnitude of displacement?
12. Define distance, displacement, speed, velocity and
acceleration.
26. What is acceleration due to gravity?
27. A bus moves by 8 m from its position of rest in 2 s,
along a straight road. If it covers 10 m in the next
second, it is moving with
13. Why is displacement referred to as a vector quantity?
14. Speedometer of a vehicle measures its
speed.
What are the different types of graphs that can be
Answers
Answer:
1.Mechanics may be divided into three branches: statics, which deals with forces acting on and in a body at rest; kinematics, which describes the possible motions of a body or system of bodies; and kinetics, which attempts to explain or predict the motion that will occur in a given situation.
2.Kinematics, branch of physics and a subdivision of classical mechanics concerned with the geometrically possible motion of a body or system of bodies without consideration of the forces involved (i.e., causes and effects of the motions).
3.To represent a vector geometrically, we use arrows (also known as "directed line segments"). The length of the arrow represents the vector's size, and its direction represents the vector's direction in 2-space or in 3-space.
4.Geometric Vectors. To represent a vector geometrically, we use arrows (also known as "directed line segments"). The length of the arrow represents the vector's size, and its direction represents the vector's direction in 2-space or in 3-space. ... Vectors are parallel if their shafts are parallel.
5.Displacement is minimum when the body moves in opposite direction.
Thus, minimum displacement possible
Smin =12−5=7 m
6.Rest and motion are the relative terms because they depend on the observer's frame of reference. So if two different observers are not at rest with respect to each other, then they too get different results when they observe the motion or rest of a body.
7.If someone is walking towards India gate then India gate is moving with respect to that person. If a person that is walking is considered as the reference point then it will be considered as static since the reference point is the origin and other things are seen with respect to it.
8.The person, seated in a train under motion, will be at rest with reference to the object whose relative velocity is zero. So, that person is at rest with respect to the train itself, another person watching him from the front seat and the car moving in the same direction with same speed.
9.A scalar quantity is defined as the physical quantity that has only magnitude, for example, mass and electric charge. On the other hand, a vector quantity is defined as the physical quantity that has both magnitude as well as direction like force and weight.
12.Displacement is a vector which points from the initial position of an object to its final position. The standard units of displacement are meters. Velocity is a vector which shows the direction and rate of motion. ... Acceleration is a vector which shows the direction and magnitude of changes in velocity.
13. Displacement is defined as the final distance vector minus the initial distance vector. ... Since the line has a direction, it needs to be a vector quantity. If it weren't a vector quantity, you wouldn't be able to draw it on a map at all, because it would just be a number.
(19,20,21,22,23,24,25,14)⬅️execpt these I answerd all questions.