Question

A 1.50 kg book is sliding along a rough horizontal surface. At point A, it is moving at 3.21 m/s, and at point B it has slowed to 1.25 m/s. What is the change in kinetic energy of the book as it moves from point A to point B?

1) Cannot be determined
2) 3.21 J
3) 1.25 J
4) 4.46 J

Answer 1

The change in kinetic energy of the book as it moves from point A to point B is -4.46 J.

Step-by-step explanation:

The change in kinetic energy of the book as it moves from point A to point B can be calculated using the formula: ΔKE = ½ m (vB² - vA²), where m is the mass of the book, vB is the velocity of the book at point B, and vA is the velocity of the book at point A.

Using the given values:

• m = 1.50 kg
• vA = 3.21 m/s
• vB = 1.25 m/s

Plugging these values into the formula, we get:

ΔKE = ½ (1.50 kg) ((1.25 m/s)² - (3.21 m/s)²)

ΔKE = -4.46 J

The change in kinetic energy of the book as it moves from point A to point B is -4.46 J, which means it decreases by 4.46 Joules.