If a boat and its riders have a mass of 800 kg and the boat drifts in at 1.5 m/s how much work does Sam do to stop it?

but do not forget the answer is negative

(1/2) m v^2 = 400(2.25) Joules

Well, let's see. If Sam is stopping the boat, that means he's exerting a force in the opposite direction of its motion. But since you brought me into this, I'll need to know if he's wearing clown shoes or not. It makes a big difference, you know!

To calculate the work done by Sam to stop the boat, we need to use the equation:

Work = Force × Distance

Since the boat is drifting, we can assume that the only force acting on it is the force of friction. Let's denote the force of friction as F_friction.

The work done by Sam to stop the boat is equal to the work done by the force of friction. Therefore:

Work = F_friction × Distance

We also know that the work done is equal to the change in kinetic energy (KE) of the boat. So:

Work = ΔKE

To calculate ΔKE, we can use the equation:

ΔKE = ½ × m × (vf^2 - vi^2)

Where:
m = mass of the boat and its riders = 800 kg
vf = final velocity = 0 m/s (since the boat is stopped)
vi = initial velocity = 1.5 m/s (given)

Now let's calculate the work done by Sam to stop the boat:

ΔKE = ½ × 800 kg × (0^2 - 1.5^2)
= ½ × 800 kg × (-1.5^2)
= ½ × 800 kg × (-2.25)
= -900 J (since work is scalar and the negative sign indicates that work is done against the direction of motion)

Therefore, the work done by Sam to stop the boat is -900 Joules (J).

To calculate the work done by Sam to stop the boat, we need to use the work-energy principle, which states that the work done on an object is equal to the change in its kinetic energy.

The initial kinetic energy of the boat can be calculated using the formula:

Kinetic energy = (1/2) * mass * velocity^2

Given:
Mass of the boat = 800 kg
Initial velocity = 1.5 m/s

Substituting the values into the formula, we have:

Initial kinetic energy = (1/2) * 800 kg * (1.5 m/s)^2

Now, since Sam wants to stop the boat, the final velocity of the boat will be zero (0 m/s). Therefore, the final kinetic energy will also be zero (0 J).

The work done by Sam to stop the boat is then given by the change in kinetic energy:

Work = Final kinetic energy - Initial kinetic energy

Work = 0 J - (1/2) * 800 kg * (1.5 m/s)^2

Simplifying the equation, we get:

Work = - (1/2) * 800 kg * (1.5 m/s)^2

Evaluating the expression, we can calculate the work done by Sam to stop the boat.