A 1500 kg car starts from rest on a horizontal road and...

A $1500 \mathrm{~kg}$ car starts from rest on a horizontal road and gains a speed of $72 \mathrm{~km} / \mathrm{h}$ in $30 \mathrm{~s}$. (a) What is its kinetic energy at the end of the $30 \mathrm{~s}$ ? (b) What is the average power required of the car during the 30 s interval? (c) What is the instantaneous power at the end of the 30 s interval, assuming that the acceleration is constant?

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Constant Acceleration and Kinematics

When acceleration is constant, the relationships between velocity, time, and displacement can be described using kinematic equations. This concept allows for the analysis of moving objects over time, including determining instantaneous values such as speed or power when forces and motions change uniformly.

Power

Power is the rate at which work is done or energy is transferred over time. It is quantified as energy per unit time and is key in determining how quickly a system can perform work. In problems involving motion, distinguishing between average power, which considers the total work done over a given time, and instantaneous power, which reflects the power at a specific moment, is essential.

Kinetic Energy

Kinetic energy is the energy an object possesses due to its motion, calculated by the formula KE = 0.5 * m * v². This concept is fundamental to understanding how work is transformed into energy when an object's velocity changes, and it plays a crucial role in analyzing systems in mechanics.

Transcript

Please give Ace some feedback