Final answer:
The kinetic energy of a 6.57 kg ball rolling at 7 m/s is approximately 161 joules (J) before it hits the curb, calculated using the formula KE = 1/2mv².
Step-by-step explanation:
To calculate the kinetic energy (KE) of a ball with a mass of 6.57 kg rolling at a speed of 7 m/s before it hits the curb, we can use the formula KE = 1/2mv² where m is the mass and v is the velocity of the object. Plugging in the values:
KE = 1/2 × 6.57 kg × (7 m/s)²
KE = 1/2 × 6.57 kg × 49 m²/s²
KE = 1/2 × 6.57 kg × 49 J
KE = 3.285 kg × 49 J
KE = 160.965 J
Therefore, the kinetic energy of the ball is approximately 161 J.