Final answer:
The kinetic energy of a bead with a mass of 5 kg moving at 20 m/s is calculated using the formula 0.5 × mass × velocity squared, resulting in 1000 Joules.
Step-by-step explanation:
The student asked what the kinetic energy of a bead is if it is moving with a speed of 20 m/s and has a mass of 5 kg. The formula for calculating kinetic energy (K) is given by K = 0.5 × m × v², where m is the mass of the object and v is the velocity. Plugging in the given values: K = 0.5 × 5 kg × (20 m/s)² leads to the kinetic energy of the bead being K = 0.5 × 5 kg × 400 m²/s² = 1000 J. Therefore, the correct answer is d) 1000 J.