Answer :
The mass of the softball, when thrown with 145 Joules of kinetic energy at a velocity of 20.0 m/s, is found to be 0.725 kg using the kinetic energy formula.
To find the mass of the softball using the given kinetic energy and velocity, we will use the kinetic energy formula, which is KE = 0.5 times m times v², where KE is kinetic energy, m is mass, and v is velocity. Plugging the given values into this equation, we get:
145 J = 0.5 times m times (20.0 m/s)²
Now, we solve for m (mass):
145 J = 0.5 times m times 400 m²/s²
Therefore, m = fraction{145 J}{200 m²/s²} = 0.725 kg
So, the mass of the softball is 0.725 kg.