Which object has the greatest kinetic energy?(1 point)
Responses
a blue car with a mass of 500 kg moving at 30 m/s
a blue car with a mass of 500 kg moving at 30 m/s
a red car mass of 500 kg moving at 3 m/s
a red car mass of 500 kg moving at 3 m/s
a yellow car with a mass of 500 kg moving at 12 m/s
a yellow car with a mass of 500 kg moving at 12 m/s
a green car with a mass of 500kg moving at 21 m/s
The object with the greatest kinetic energy is the green car with a mass of 500kg moving at 21 m/s.
Use the image to answer the question.
An illustration shows a person running after a rabbit. The person weighs 60 kilograms, and the rabbit weighs 4 kilograms. The speed of both is 5 meters per second.
A wildlife keeper is trying to catch an escaping rabbit. Who has the greater kinetic energy, the rabbit or the wildlife keeper?
(1 point)
Responses
Neither one because they are moving at the same speed.
Neither one because they are moving at the same speed.
The rabbit because it has less mass.
The rabbit because it has less mass.
The wildlife keeper because they have a greater mass.
The wildlife keeper because they have a greater mass.
The wildlife keeper because they speed up and catch the rabbit.
The wildlife keeper because they speed up and catch the rabbit.
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The wildlife keeper has the greater kinetic energy because they have a greater mass, even though they are moving at the same speed as the rabbit.
A skydiver jumps out of a plane and begins to accelerate. His speed increases to 20 m/s, then 30 m/s. His acceleration slows until he reaches a constant speed of 50 m/s. Which statement correctly describes his kinetic energy during this time?(1 point)
Responses
His kinetic energy would remain the same for the whole fall as long as he lost no mass.
His kinetic energy would remain the same for the whole fall as long as he lost no mass.
His kinetic energy was positive at first, but it decreased to zero when he stopped accelerating.
His kinetic energy was positive at first, but it decreased to zero when he stopped accelerating.
His kinetic energy increased while his speed increases, then it became constant.
His kinetic energy increased while his speed increases, then it became constant.
His kinetic energy increased quickly at first, then it increased at a constant rate.
His kinetic energy increased quickly at first, then it increased at a constant rate.
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His kinetic energy increased while his speed increases, then it became constant.
To determine which object has the greatest kinetic energy, we need to use the formula for kinetic energy, which is given by:
Kinetic Energy = (1/2) * Mass * Velocity^2
Let's calculate the kinetic energy for each object:
1) Blue car mass of 500 kg moving at 30 m/s:
Kinetic Energy = (1/2) * 500 kg * (30 m/s)^2
Kinetic Energy = 1/2 * 500 kg * 900 m^2/s^2
Kinetic Energy = 225,000 kg * m^2/s^2
2) Red car mass of 500 kg moving at 3 m/s:
Kinetic Energy = (1/2) * 500 kg * (3 m/s)^2
Kinetic Energy = 1/2 * 500 kg * 9 m^2/s^2
Kinetic Energy = 2,250 kg * m^2/s^2
3) Yellow car mass of 500 kg moving at 12 m/s:
Kinetic Energy = (1/2) * 500 kg * (12 m/s)^2
Kinetic Energy = 1/2 * 500 kg * 144 m^2/s^2
Kinetic Energy = 36,000 kg * m^2/s^2
4) Green car mass of 500 kg moving at 21 m/s:
Kinetic Energy = (1/2) * 500 kg * (21 m/s)^2
Kinetic Energy = 1/2 * 500 kg * 441 m^2/s^2
Kinetic Energy = 110,250 kg * m^2/s^2
Comparing the kinetic energies calculated for each object, we can conclude that the object with the greatest kinetic energy is the blue car with a mass of 500 kg moving at 30 m/s, with a kinetic energy of 225,000 kg * m^2/s^2.
To determine which object has the greatest kinetic energy, we need to use the formula for kinetic energy:
Kinetic Energy = 1/2 * mass * velocity^2.
Now let's calculate the kinetic energy for each object using the given masses and velocities:
For the blue car:
Kinetic Energy = 1/2 * 500 kg * (30 m/s)^2 = 225,000 Joules.
For the red car:
Kinetic Energy = 1/2 * 500 kg * (3 m/s)^2 = 2,250 Joules.
For the yellow car:
Kinetic Energy = 1/2 * 500 kg * (12 m/s)^2 = 36,000 Joules.
For the green car:
Kinetic Energy = 1/2 * 500 kg * (21 m/s)^2 = 110,250 Joules.
Comparing these values, we can conclude that the blue car with a mass of 500 kg moving at 30 m/s has the greatest kinetic energy, which is 225,000 Joules.