Final answer:
To determine the input energy required to lift a rock using a lever, calculate the work done using the formula Work = Force × Distance, resulting in 90 Joules necessary to lift a 150 N weight through 0.6 meters using a lever.
Step-by-step explanation:
The question asks, How much input energy is needed to lift a rock of weight 150 N through a distance of 0.6 m using a lever? To find the input energy required, we use the work formula, which in physics is given by the equation Work (W) = Force (F) × Distance (d). Here, the force is the weight of the rock, and the distance is how far it is lifted.
By calculating the work done or energy required, you get W = F × d = 150 N × 0.6 m = 90 Joules. Therefore, the correct answer is A. 90 J. This is because work done against gravity to lift an object through a certain height is equal to the gravitational potential energy gained by the object, which is independent of the method used for lifting, assuming no energy losses due to inefficiency.