Explanation

The springs in brakes and clutches are used to restore the original position of the components after they have been engaged or disengaged.

For example, in a brake system, the springs return the brake pads to their original position after the brake pedal is released.

Similarly, in a clutch system, the springs return the clutch plate to its original position after the clutch pedal is released.

Explanation

The stability of a racing car is increased by lowering its center of gravity, which reduces the risk of rollover or loss of control.

This can be achieved through design elements like a lower ride height, a wider stance, or a lower seating position for the driver.

Explanation

A tightrope walker carries a long pole to lower their center of gravity, making it easier to balance and maintain equilibrium.

By spreading their weight over a larger area (including the pole), they reduce the risk of toppling over.

Explanation

A Bunsen burner is made more stable by increasing its base area, which lowers its center of gravity and makes it less likely to tip over.

This is a common design principle in engineering, where a wider base provides greater stability.

Explanation

When a body is in unstable equilibrium, a slight tilt will cause its center of gravity (CG) to remain above the point of contact, making it prone to toppling over or falling.

This means that the CG is not directly over the point of support, but is still above it, creating a moment that tends to rotate the body further.

Key Points:

• A body is in stable equilibrium after slight tilt if its center of gravity remains above the point of contact.
• A body is in neutral equilibrium when its center of gravity remains at same height.

Explanation

When a body is tilted slightly, if its center of gravity remains above the point of contact, it will tend to return to its original position, restoring equilibrium.

This is a characteristic of stable equilibrium.

Key Points:

• A body is in unstable equilibrium after slight tilt if its center of gravity remains above the point of contact.
• A body is in neutral equilibrium when its center of gravity remains at same height.

Explanation

The vertical component of the force is:

Vertical component = Force × sin(angle)

= 15 N × sin(60°)

= 15 N × 0.866

= 13 N

So, the vertical component of the 15 N force at an angle of 60° is approximately 13 N.

Explanation

The head-to-tail rule is a method for adding vectors, such as forces, by lining up the head of one vector with the tail of the next vector.

This rule can be used to add any number of forces, not just two or three.

Explanation

To find the acceleration of the sledge, we can use Newton's second law of motion: F = ma, where F is the net force acting on the sledge, m is its mass, and a is its acceleration.

First, we need to find the net force acting on the sledge. The force applied by the man is 60 N, and the force of friction is 20 N, so the net force is:

F = 60 N - 20 N = 40 N

Next, we can plug in the values to Newton's second law:

40 N = (25 kg) × a

To find the acceleration, we can divide both sides by the mass:

a = 40 N / 25 kg = 1.6 ms^-2

Therefore, the acceleration of the sledge is 1.6 ms^-2.

Explanation

Limiting frictional force (also known as static friction) is greater than:

• Rolling friction (because rolling friction is much smaller, as it only opposes the motion of an object that is already rolling)
• Sliding friction (which is another term for kinetic friction)
• Kinetic friction (which is the frictional force that acts when an object is already moving)