Two bullets have masses of 3.0 g and 6,0 g, respectively. Both are fired with a speed of 40.0 m/s. Which bullet has more kinetic energy? What is the ratio of their kinetic energies?
The kinetic energy of an object is given by the equation:
KE = (1/2)mv^2
where KE is the kinetic energy, m is the mass, and v is the velocity/speed.
For the first bullet with a mass of 3.0 g (0.003 kg) and speed of 40.0 m/s, its kinetic energy is:
KE1 = (1/2)(0.003 kg)(40.0 m/s)^2 = 2.4 J (rounded to one decimal place)
For the second bullet with a mass of 6.0 g (0.006 kg) and speed of 40.0 m/s, its kinetic energy is:
KE2 = (1/2)(0.006 kg)(40.0 m/s)^2 = 4.8 J (rounded to one decimal place)
Therefore, the second bullet with a mass of 6.0 g has more kinetic energy compared to the first bullet with a mass of 3.0 g.
The ratio of their kinetic energies is:
KE2/KE1 = 4.8 J / 2.4 J = 2
Therefore, the ratio of their kinetic energies is 2, meaning the second bullet has double the kinetic energy of the first bullet.