4. How much kinetic energy does a 2 kg toy car have if it is moving at 3m/s 5. Which has the greater effect on the kinetic energy, the mass or the velocity, or are the equal?

4. **Kinetic Energy Calculation:**<br /><br />The formula for kinetic energy is KE = (1/2)mv², where KE is kinetic energy, m is mass, and v is velocity.<br /><br />In this case, m = 2 kg and v = 3 m/s. Plugging these values into the formula:<br /><br />KE = (1/2) * 2 kg * (3 m/s)²<br />KE = 1 kg * 9 m²/s²<br />KE = 9 Joules<br /><br />Therefore, the toy car has 9 Joules of kinetic energy.<br /><br /><br />5. **Effect of Mass and Velocity on Kinetic Energy:**<br /><br />Velocity has a greater effect on kinetic energy than mass. This is because velocity is squared in the kinetic energy formula, while mass is not. <br /><br />Let's illustrate with an example:<br /><br />* **Doubling the mass:** If you double the mass (keeping velocity constant), you double the kinetic energy.<br />* **Doubling the velocity:** If you double the velocity (keeping mass constant), you quadruple the kinetic energy (because 2² = 4).<br /><br />Therefore, a change in velocity has a more significant impact on kinetic energy than an equivalent change in mass.<br />