Final answer:
The block moved at a velocity of 1.3 m/s after 15 J of work were expended to move the 18 kg block.
Step-by-step explanation:
Velocity is the speed in combination with the direction of motion of an object. Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies. Velocity is a physical vector quantity: both magnitude and direction are needed to define it.
The find out at what velocity an 18 kg block moved when 15 J of work were expended to move it. To solve this, we can use the work-energy principle, which states that work done on an object is equal to the change in its kinetic energy. The formula for work done (W) is W = ½ m v^2, where m is the mass of the object and v is the velocity.
Let's rearrange the formula to solve for velocity: v = √(2W/m). Plugging in the given values, v = √(2×15 J / 18 kg), which equals approximately √(30/18) m/s or √1.666 m/s. When calculated, this gives a velocity of around 1.29 m/s, which rounded to one decimal place is 1.3 m/s. Therefore, the block moved at a velocity of 1.3 m/s.