# Work and Kinetic Energy

• Richober
In summary, the conversation discusses the calculation of work done on an ice block being pushed through a displacement of (15m)i -(12m)j by a force of (210N)i -(150N)j. The Pythagorean theorem is used to determine the magnitude of the displacement and force vectors, and the work done is calculated using the equation W=Fxd. The questioner is unsure if they set up the problem correctly and asks for clarification on the definition of work.

## Homework Statement

An ice block is being pushed through a displacement d→=(15m)i -(12m)j along an embankment with rushing water. It exerts F→=(210N)i -(150N)J on block. How much work on block does force do?

## Homework Equations

W=Fxd
Pythogoreum equation
a^2 +b^2= c^2

## The Attempt at a Solution

I drew i and j coordinates for both displacement vector and force vector. I calculated
d→=15^2 + 12^2= c^2
d→=c=19.21m
I used same for F→
(210N)^2 + (150N)^2 = c^2
c=258.07 N
W=Fxd
(258.07N)* (19.21m) = 4957.52 J
I think I might have set it up wrong.

Richober said:

## Homework Statement

An ice block is being pushed through a displacement d→=(15m)i -(12m)j along an embankment with rushing water. It exerts F→=(210N)i -(150N)J on block. How much work on block does force do?

## Homework Equations

W=Fxd
Pythogoreum equation
a^2 +b^2= c^2

## The Attempt at a Solution

I drew i and j coordinates for both displacement vector and force vector. I calculated
d→=15^2 + 12^2= c^2
d→=c=19.21m
I used same for F→
(210N)^2 + (150N)^2 = c^2
c=258.07 N
W=Fxd
(258.07N)* (19.21m) = 4957.52 J
I think I might have set it up wrong.
Hello Richober. Welcome to PF !

What is the definition of work?

Not only are force, ##\ \vec{F}\,,\ ## and displacement, ##\ \vec{d}\,,\ ##involved, their relative directions must also be included..

## What is work?

Work is defined as the product of force and displacement, where the force is applied in the same direction as the displacement.

## What is kinetic energy?

Kinetic energy is the energy an object possesses due to its motion. It is calculated as one-half times the mass of the object multiplied by its velocity squared.

## How are work and kinetic energy related?

Work is directly related to kinetic energy, as work done on an object causes a change in its kinetic energy. This can be seen through the work-energy theorem, which states that the net work done on an object is equal to the change in its kinetic energy.

## What is the unit of measurement for work and kinetic energy?

The unit for both work and kinetic energy is the joule (J) in the SI system. In terms of base units, it is equal to kg*m^2/s^2.

## Can kinetic energy be negative?

In most cases, kinetic energy cannot be negative as it is a measure of an object's motion. However, in certain scenarios such as deceleration or negative work being done on an object, its kinetic energy can become negative. This indicates a decrease in the object's motion or speed.