the faster an object moves, the __ kinetic energy it has. more or less?
The correct answer and explanation is:
Correct Answer: More
The faster an object moves, the more kinetic energy it has. This is because kinetic energy is directly related to both the mass of an object and the square of its velocity.
The formula for kinetic energy (KE) is: KE=12mv2KE = \frac{1}{2}mv^2
Where:
- KEKE is kinetic energy
- mm is mass
- vv is velocity
As you can see from the equation, velocity (vv) is squared. This means that even a small increase in speed will lead to a significantly larger increase in kinetic energy. For example, if you double the speed of an object, its kinetic energy increases by a factor of four (22=42^2 = 4). If you triple the speed, the kinetic energy increases nine times (32=93^2 = 9).
Let’s say a 1-kg object moves at 2 meters per second: KE=12(1)(22)=12(4)=2 joulesKE = \frac{1}{2}(1)(2^2) = \frac{1}{2}(4) = 2 \text{ joules}
Now increase the speed to 4 m/s: KE=12(1)(42)=12(16)=8 joulesKE = \frac{1}{2}(1)(4^2) = \frac{1}{2}(16) = 8 \text{ joules}
So, the kinetic energy quadrupled when the speed doubled. This is why fast-moving objects, such as cars or falling rocks, can do a lot of damage—they have more kinetic energy to transfer upon impact.
In summary, because kinetic energy depends on the square of velocity, faster objects always have more kinetic energy, assuming their mass remains constant. This concept is essential in physics, engineering, safety design, and everyday life.