what is the kinetic energy in joules of a 1040-kg automobile traveling at 81 km/h ?
Convert the speed to meters per second, and then compute (1/2)M*V^2
That will be the kinetic energy, in Joules.
To calculate the kinetic energy of an object, we can use the formula:
Kinetic Energy = 1/2 * mass * velocity^2
First, we need to convert the given mass from kilograms to grams. Since 1 kilogram is equal to 1000 grams, the mass of the automobile in grams is:
1040 kg * 1000 g/kg = 1040000 grams
Next, we need to convert the given velocity from kilometers per hour (km/h) to meters per second (m/s). The conversion factor for this is:
1 km/h = 1000 m/3600 s
So, the velocity of the automobile in meters per second is:
81 km/h * (1000 m/3600 s) = 22.5 m/s
Now, we can use the kinetic energy formula to find the answer:
Kinetic Energy = 1/2 * mass * velocity^2
= 1/2 * 1040000 g * (22.5 m/s)^2
First, let's square the velocity:
(22.5 m/s)^2 = 22.5 m/s * 22.5 m/s = 506.25 m^2/s^2
Now, we can substitute this into the formula:
Kinetic Energy = 1/2 * 1040000 g * 506.25 m^2/s^2
To simplify the calculation, we can express grams in terms of kilograms (1 kg = 1000 g):
Kinetic Energy = 1/2 * 1040 kg * 506.25 m^2/s^2
Now we can calculate the kinetic energy using a calculator:
Kinetic Energy ≈ 26310000 Joules
Therefore, the kinetic energy of a 1040-kg automobile traveling at 81 km/h is approximately 26,310,000 Joules.