What is work against gravity and friction?

For example, when you lift weights , you do work against gravity. You apply a force upwards . Friction is the force that is resisting the motion of an object so it will always point in the opposite direction of that of movement. For example, when an object is sliding on a table it does work against friction .

Is work done against friction negative?

The work done by frictional force will be positive when the displacement of the body is in the direction of the force. Since, the direction of motion of the block and the direction of frictional force is opposite to each other, the work done by friction is negative. The work done by friction can also be zero.

What is work against friction Class 9?

Work against friction Force is to be applied to move, roll, or drag a body over a surface of another body. Example: If an object is dragged to a certain distance (d).

Can work done by static friction be positive?

Positive work – The work done by static friction on an object moving along with (without slipping) an accelerating belt is positive with respect to the ground frame as the displacement and the friction force act along the same direction (along the direction of acceleration).

Can friction do positive work explain?

Friction, by its nature, always acts opposing the relative motion between two surfaces. work done by friction can be zero, when there is no relative motion. But positive work cannot be done under any circumstances, if you see it from a reference frame fixed to one of the two surfaces.

What is the work of friction force?

The force of friction is always exerted in a direction that opposes movement (for kinetic friction) or potential movement (for static friction) between the two surfaces. For example, a curling stone sliding along the ice experiences a kinetic force slowing it down.

What is the formula of work against friction?

This energy is consumed by force of friction that acts opposite to the direction of motion. In fact, it is the work done by force of friction. Solution: Using Work formula: W = Fk x ; -112,000J = Fk(56m); Fk =-2000N.

Is work done by static friction is zero?

Basically static friction can also act when a body is in equilibrium and hence displacement is zero and hence work done by static friction is zero.

What is negative friction?

Negative friction coefficients arise when the friction force increases with decreasing load. As the load is reduced, however, the friction force first increases and then levels off until the surfaces pull free from each other.

What is positive and negative work?

Positive work done – The work done is said to be positive when force and displacement are in the same direction. Negative work done – The work done is said to be negative when force and displacement are in opposite directions.

Can friction force do work?

Static Friction can Perform External Work As an external force, however, static friction can do work. This may seem odd, since “static” generally implies no motion. It is important to remember, however, that static in this context means static relative to the surface of contact.

Can work be negative physics?

The work that is done can be positive work or negative work depending on whether the force doing the work is directed opposite the object’s motion or in the same direction as the object’s motion.