(a) The centre of gravity of a triangular lamina is at the intersection of its medians. (b) The center of gravity of a circular lamina is at the center of the circular lamina
What is the position of the center of gravity of a: (a) rectangular lamina (b) cylinder?
(a) The point of intersection of a rectangular lamina's diagonals is where the lamina's center of gravity is located. (b) A cylinder's center of gravity is located at the midway of the cylinder's...
Is centrifugal force a real force?
Centrifugal force, on the other hand, is a made-up force.
Explain the motion of a planet around the sun in a circular path.
A planet orbits the sun in a circular path, with the sun's gravitational force providing the necessary centripetal force to allow the planet to move in a circular path.
What is centripetal force?
The centripetal force is the force acting on a body travelling in a circular path in the direction of the circular path's center.
Name the force required for circular motion. State its direction.
Circular motion necessitates the application of centripetal force. The direction of centripetal force is always in the direction of the circle's center.
A uniform circular motion is an accelerated motion. Explain it. State whether the acceleration is uniform or variable? Name the force responsible to cause this acceleration. What is the direction of force at any instant? Draw diagram in support of your answer.
When an object goes on a circular path at a constant speed, the amount of its velocity does not change; it just changes its direction. As a result, it's referred to as consistently accelerated motion.
State factor on which the position of the center of gravity of a body depend? Explain your answer with an example.
The center of gravity of a body with a certain mass position is determined by its form, or the distribution of mass. The center of gravity, for example, is found in the middle of a uniform wire....
Give one example of motion in which speed remains uniform, but the velocity changes.
The motion of a cyclist on a circular track is an example of motion in which the speed is constant but the velocity varies.
Is it possible to have an accelerated motion with a constant speed? Name such type of motion.
Yes, an accelerated motion with a constant speed is feasible. Uniform circular motion is an example of this type of motion.
Draw a neat labelled diagram for a particle moving in a circular path with a constant speed. In your diagram show the direction of velocity at any instant.
A particle moves in a circular route at a constant speed.
Can the center of gravity of a body be situated outside its material of the body? Give an example.
Yes, a body's centre of gravity can be located outside of the body's substance. A ring's center of gravity is an example.
Define the term ‘center of gravity of a body’.
The algebraic sum of moments of weights of particles composing the body is zero at the Centre of gravity of a body, and the total weight of the body is assumed to act at this location.
Explain the meaning of uniform circular motion. Why is such motion said to be accelerated?
When a particle moves at a constant speed in a circular path, it is said to be in a circular motion. The rotation of the Earth around the sun, for example, is an example of uniform circular motion.
A, B and C are the three forces each of magnitude 4N acting in the plane of the paper as shown in Figure. The point O lies in the same plane. (i) Name the forces producing (a) clockwise and (b) anticlockwise moments.
(i) (a) Clockwise moments are produced by vectors A and B. Explanation: Moment of force is called clockwise moment and it is negative if the turning impact on the body is clockwise. (b)...
A, B and C are the three forces each of magnitude 4N acting in the plane of the paper as shown in Figure. The point O lies in the same plane. (i) Which force has the least moment about O? Give a reason. (ii) Which force has the greatest moment about O? Give a reason.
(i) Moment of force= Force x Perpendicular distance, as we all know. Because the perpendicular distance between vector C and point O is the shortest, As a result, vector C will have the smallest...
Complete the following sentences: (i) In a beam balance when the beam is balanced in a horizontal position, it is in ____________equilibrium. (ii) The moon revolving around the earth is in ____________ equilibrium.
(i) In beam balancing, the beam is in static equilibrium when it is balanced in a horizontal position. (ii) The moon is in dynamic balance as it revolves around the earth.
Complete the following sentences:(i) The S.I. unit of moment of force is _________. (ii) In equilibrium algebraic sum of moments of all forces about the point of rotation is ______________.
(i) The Newton meter is the SI unit of moment of force. (Nm) (ii) The algebraic sum of moments of all forces around the point of rotation is zero in equilibrium.
Describe a simple experiment to verify the principle of moments, if you are supplied with a meter rule, a fulcrum and two springs with slotted weights.
Suspend a meter rule horizontally from a fixed support at point O using a strong thread. W1 and W2 now suspend two spring balances on either side of the thread with slotted weights. The meter rule...
State the principle of moments. Name one device based on it.
According to the principle of moments " the body is considered to be in equilibrium if the algebraic total of moments about the axis of rotation of all the forces operating on it is zero." A beam...
State two conditions for a body, acted upon by several forces to be in equilibrium.
The two conditions for a body to be in equilibrium are: (i)The resultant of all forces acting on a body must be zero, which is one of the two requirements for a body to be in equilibrium. (ii)All...
State the condition when a body is in (i) static, (ii) dynamic equilibrium. Give one example each of static and dynamic equilibrium.
(i) When the body remains in a condition of rest while being influenced by various forces, it is said to be in static equilibrium. Example: A book on a table is in a state of static equilibrium....
What do you mean by equilibrium of a body?
A body is to be in equilibrium when a number of forces operating on it generate no change in its state of rest, linear, or rotational motion.
Prove that Moment of couple = Force x Couple arm.
Two equal and opposite forces, each of magnitude F, are applied at points A and B. The bar is rotated in an anticlockwise manner by the two forces. The coupling arm, or AB, is the perpendicular...
Define the moment of a couple. Write its S.I unit.
The product of both force and the perpendicular distance between the two forces equals the couple's moment. The S.I unit of moment of couple is Nm
What do you understand by the term couple? State its effect. Give two examples in our daily life where a couple is applied to turn a body.
A pair is formed by two equal and opposite parallel pressures that are not acting along the same line. The rotation must always be produced by a couple. Rotating a key in a lock and turning the...
Draw a neat labelled diagram to show the direction of two forces acting on a body to produce rotation in it. Also mark the point O about which the rotation takes place.
Two forces of magnitude F are applied at A and B, which are equal and opposite forces. The two forces rotate the bar in an anticlockwise direction, as seen in the diagram above.
A body is acted upon by two forces each of magnitude F, but in opposite directions. State the effect of the forces if (a)both forces act at the same point of the body. (b)the two forces act at two different points of the body at a separation r.
(a) The resultant force acting on the body = 0 $F-F\text{ }=\text{ }0$ (b) The forces tend to rotate the body between two forces about the midpoint. Moment of forces = $F\text{ }\times \text{ }r$...
The adjacent diagram shows a heavy roller, with its axle at O, which is to be raised on a pavement XY. If there is friction between the roller and pavement, show by an arrow on the diagram the point of application and the direction of force to be applied.
Force F should be applied in the direction as shown in the above figure.
The stone of hand flour grinder is provided with a handle near its rim. Give a reason.
The stone of a hand flour grinder has a handle near its rim because it may be spun easily around the iron pivot at its center by applying modest force to the handle.
It is easier to turn the steering wheel of a large diameter than that of a small diameter. Give reason.
Turning a wide diameter steering wheel with a large distance from the centre of the rim requires less force. As a result, turning a large diameter steering wheel is easier than turning a small...
A jackscrew is provided with a long arm. Explain why?
A jackscrew with a long arm that is used to hoist a heavy load, such as a vehicle, will require less effort to rotate in order to raise or lower the jack. As a result, the jackscrew's arm is quite...
A spanner (or wrench) has a long handle. Why?
The long handle of the spanner creates a bigger turning moment, making it easier to turn the nut with less force. As a result, the spanner's handle is quite long.
When does a body rotate? State one way to change the direction of rotation of a body. Give a suitable example to explain your answer.
When the body is pivoted at a point, a force applied at a suitable position spins the body about the axis passing through the pivoted point. The point of application of force can be altered to...
Why is it easier to open a door by applying the force at the free end of it?
More the perpendicular distance the less effort is the required to turn the body and because of which we can conclude that it is easier to open a door by exerting force at the free end of it.
State one way to obtain a greater moment of a force about a given axis of rotation.
Increasing the distance from the axis of rotation where the force would act as Moment of force is equal to the product of force and the perpendicular distance of force from the axis of rotation is...
State one way to reduce the moment of a given force about a given axis of rotation.
The perpendicular distance between the line of force action and the axis of rotation determines the moment of force. As a result, one technique to lower the moment of a given force about a given...
What do you understand by the clockwise and anticlockwise moment of force? When is it taken positive?
The moment of force is define as the anticlockwise moment when the effect on the body is to turn the body anticlockwise so the clockwise moment is when the effect is to turn the body clockwise. The...
Write the expression for the moment of force about a given axis.
The moment of force is defined as:- Moment of a force = Force perpendicular distance of force from rotation axis.
Define the moment of force and state its S.I. unit.
Product of the magnitude of the force (newton) and the force's perpendicular distance of the line of action from axis of rotation is termed as the moment of force (meter). Newton meter = Newton...
State two factors affecting the turning effect of a force.
(1) The size of the applied force is one of the two parameters that affects the turning effect of a force. (2) The distance between the force's line of action and the axis of rotation.
State whether the moment of force is a scalar or vector quantity?
It (the moment of force) is a vector quantity, meaning it has both a magnitude and a direction.
State the condition when applying a force, the body has:(a)the translational motion, (b)the rotational motion.
(a) The state in which the body produces translational motion when it is free to move when a force is applied. (b) The state in which the body produces rotational motion when it is pivoted at a...