A cyclist accelerates from rest to a speed of 15 m/s. If the mass of the cyclist and the bicycle is 75 kg, what is the kinetic energy at that speed?
Practice Questions
1 question
Q1
A cyclist accelerates from rest to a speed of 15 m/s. If the mass of the cyclist and the bicycle is 75 kg, what is the kinetic energy at that speed?
500 J
750 J
1000 J
1250 J
Kinetic Energy = 0.5 × mass × velocity² = 0.5 × 75 kg × (15 m/s)² = 8437.5 J.
Questions & Step-by-step Solutions
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Q
Q: A cyclist accelerates from rest to a speed of 15 m/s. If the mass of the cyclist and the bicycle is 75 kg, what is the kinetic energy at that speed?
Solution: Kinetic Energy = 0.5 × mass × velocity² = 0.5 × 75 kg × (15 m/s)² = 8437.5 J.
Steps: 7
Step 1: Identify the formula for kinetic energy, which is Kinetic Energy = 0.5 × mass × velocity².
Step 2: Write down the mass of the cyclist and bicycle, which is 75 kg.
Step 3: Write down the final speed of the cyclist, which is 15 m/s.
Step 4: Substitute the values into the formula: Kinetic Energy = 0.5 × 75 kg × (15 m/s)².
Step 5: Calculate (15 m/s)², which is 225 m²/s².
Step 6: Multiply 75 kg by 225 m²/s² to get 16875 kg·m²/s².
Step 7: Multiply 16875 by 0.5 to find the kinetic energy: 0.5 × 16875 = 8437.5 J.
