A car accelerates from rest to a speed of 20 m/s. If its mass is 1000 kg, what i
Practice Questions
Q1
A car accelerates from rest to a speed of 20 m/s. If its mass is 1000 kg, what is the kinetic energy of the car at that speed?
200,000 J
100,000 J
50,000 J
400,000 J
Questions & Step-by-Step Solutions
A car accelerates from rest to a speed of 20 m/s. If its mass is 1000 kg, what is the kinetic energy of the car at that speed?
Step 1: Identify the formula for kinetic energy (KE). The formula is KE = 0.5 × m × v².
Step 2: Identify the mass (m) of the car. The mass is given as 1000 kg.
Step 3: Identify the speed (v) of the car. The speed is given as 20 m/s.
Step 4: Substitute the values into the formula. KE = 0.5 × 1000 kg × (20 m/s)².
Step 5: Calculate (20 m/s)². This equals 400 m²/s².
Step 6: Substitute the squared value back into the equation. KE = 0.5 × 1000 kg × 400 m²/s².
Step 7: Multiply 0.5 by 1000. This equals 500.
Step 8: Multiply 500 by 400. This equals 200,000 J.
Step 9: Conclude that the kinetic energy of the car at 20 m/s is 200,000 Joules.
Kinetic Energy – Kinetic energy is the energy an object possesses due to its motion, calculated using the formula KE = 0.5 × m × v², where m is mass and v is velocity.
Units of Measurement – Understanding the units involved in the calculation, such as kilograms for mass and meters per second for velocity, is crucial for accurate computation.