Mechanics (Physics) (Part-2)

Total Questions: 49

41. _______is the external agency applied on a body to change its state of rest or uniform motion. [S.S.C. Online Graduation Level (T-I) 18.08.2021 (Shift-I)]

Correct Answer: (b) Force
Solution:Force is that external factor or agency, that, when applied to a stationary object or an object moving with uniform speed, causes a change in the stationary state or uniform speed of the object.

Actions like picking, opening, shutting, kicking, hitting, lifting, flicking, pushing, and pulling are often used to describe certain tasks.

Each of these actions usually results in some kind of change in the state of motion of an object.

42. What is inertia? [S.S.C. Online CHSL (T-I) 21.01.2017 (Shift-II)]

Correct Answer: (a) Tendency to resist change in the present situation
Solution:If an object is at rest or in a kinetic state, it will remain in that position until an external force is applied to it.
The tendency of objects to change their state of rest or motion on their own is called inertia.Hence option (a) will be the correct answer.

43. Which of the following quantities is a measure of inertia? [S.S.C. Online C.P.O.S.L. (T-I) 2.07.2017 (Shift-I)]

Correct Answer: (c) Mass
Solution:Mass is that quantity, that is completely dependent on inertia.

The greater the inertia of an object, the greater the mass of that object

44. The inertia of an object is measured by its ______ . [S.S.C. Online CHSL (T-I) 5.08.2021 (Shift-II)]

Correct Answer: (c) mass
Solution:The inertia of an object can be measured by its mass.
Mass is a measure of inertia of the object, for an object, its inertia would depend on its mass.
Explanation:

Inertia is the tendency of an object to resist any change in its motion (whether at rest or in motion).
The greater the mass, the greater the inertia.

For example, a truck has more inertia than a bicycle.

45. A safety seat belt in a car exerts a force on our body to: [S.S.C. JE Electrical Exam 22.03.2021 (Shift-I)]

Correct Answer: (c) Make our forward motion slower
Solution:A safety seat belt in a car exerts a force on our body to make our forward motion slower.

When we travel in a moving car, our body remains in a state of rest with respect to the seat. But when the driver applies sudden breaks or stops the car our body tends to continue in the same state of motion because of its inertia.

Therefore, sudden breaks may cause injury to us by impact or collision, and a safety seat belt in a car exerts a force on our body to make our forward motion slower.

46. What will be the moment of inertia of a solid sphere of mass 'M' and radius 'R' about on the axis passing through its centre? [S.S.C. Online Constable GD 3.03.2019 (Shift-II)]

Correct Answer: (d) 2/5MR²
Solution:The value of moment of inertia with respect to the axis passing through the centre of a solid sphere of mass M and radius R can be expressed by the formula:

  2/5MR²

47. If the axis of rotation passes through an object while in motion, then that motion is said to be_______. [S.S.C. Online CHSL (T-I) 18.01.2017 (Shift-III)]

Correct Answer: (c) spin motion
Solution:The motion in which axis of rotation passes through the body is called spin motion.

48. The speed of a car on a straight road is an example of________motion. [S.S.C. Online MTS (T-I) 20.08.2019 (Shift-II)]

Correct Answer: (c) Rectilinear
Solution:The rectilinear motion of an object is the motion in which the object moves on a straight linear path with the direction of displacement and velocity in the same direction.

The motion of the vehicle is also on a straight path.
Thus, the motion of a vehicle on a straight road is a rectilinear motion.

49. The velocity time graph for the uniform motion of a car is: [S.S.C. JE Mechanical Exam 22.03.2021 (Shift-I)]

Correct Answer: (d) A straight line parallel to the time axis
Solution:The velocity-time graph for a uniform motion of a car will be a straight line parallel to the time axis.

So in the given graph, the slope is constantly increasing which means that it accelerates constantly after that the slope of the graph becomes constant which means that after some time it moves at a constant speed.

Draw a velocity time graph for an object in uniform motion ...