Take note that kinetic energy is directly proportional to velocity as shown in the formula:
`KE=1/2mv^2`
where m is the mass of the object in kg and v is the velocity of the object in m/s.
So when two objects have the same mass, the object with the higher velocity will have higher kinetic energy.
To show this, let's compute the kinetic energy of each box.
The first box has a mass of m=20 kg...
Take note that kinetic energy is directly proportional to velocity as shown in the formula:
`KE=1/2mv^2`
where m is the mass of the object in kg and v is the velocity of the object in m/s.
So when two objects have the same mass, the object with the higher velocity will have higher kinetic energy.
To show this, let's compute the kinetic energy of each box.
The first box has a mass of m=20 kg and its velocity is v=20 mph.
Before plugging in the values, convert the velocity from miles per hour to meter per second.
`v=20 (mi)/(h) * (1609.34m)/(1 mi) * (1h)/(3600s)=8.9408 m/s`
So, the kinetic energy of the first box is:
`KE=1/2mv^2 = 1/2(20kg)(8.9408m/s)^2=799.379J`
The second box has a mass of m=20 kg and its velocity is v=21 mph.
Convert its velocity from miles per hour to meters per second.
`v=21(mi)/h * (1609.34m)/(1 mi) * (1h)/(3600s)=9.3878`
So, the kinetic energy of the second box is:
`KE=1/2mv^2=1/2(20kg)(9.3878m/s)^2=881.3079J`
Therefore, it is the 20 kg box moving at a speed of 21 mph that has the greater amount of kinetic energy.
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