A 1000 kg car is moving at a speed of 36 km/h. What is its kinetic energy? (1 km
Practice Questions
Q1
A 1000 kg car is moving at a speed of 36 km/h. What is its kinetic energy? (1 km/h = 1/3.6 m/s) (2000)
500 J
1000 J
2000 J
5000 J
Questions & Step-by-Step Solutions
A 1000 kg car is moving at a speed of 36 km/h. What is its kinetic energy? (1 km/h = 1/3.6 m/s) (2000)
Step 1: Identify the mass of the car, which is 1000 kg.
Step 2: Identify the speed of the car, which is 36 km/h.
Step 3: Convert the speed from km/h to m/s using the conversion factor (1 km/h = 1/3.6 m/s).
Step 4: Calculate the speed in m/s: 36 km/h = 36 / 3.6 = 10 m/s.
Step 5: Use the formula for kinetic energy (KE): KE = 0.5 × m × v².
Step 6: Substitute the values into the formula: KE = 0.5 × 1000 kg × (10 m/s)².
Step 7: Calculate (10 m/s)², which is 100 m²/s².
Step 8: Multiply: 0.5 × 1000 kg × 100 m²/s² = 50000 J.
Step 9: Conclude that the kinetic energy of the car is 50000 Joules.
Kinetic Energy – Kinetic energy is the energy possessed by an object due to its motion, calculated using the formula KE = 0.5 × m × v², where m is mass and v is velocity.
Unit Conversion – Understanding how to convert units from km/h to m/s is crucial for correctly applying the kinetic energy formula.