Physics Lesson 13
A 2.74 g coin, which has zero potential energy at the surface, is dropped into a 12.2 m well. After the coin comes to a stop in the mud, what is its potential energy with respect to the surface?
-.328 J
How high would a 0.5-kg pendulum have to swing in order to have a potential energy of 2.3 J? (Assume a gravitational acceleration of 9.8 m/s/s.)
.47 M
What is the kinetic energy of a 0.135 kg baseball thrown at 40.0 m/s?
108 J
What is the potential energy of a 150-kg rock perched on a 10. m high cliff? (Use 9.8 m/s/s as the gravitational acceleration.)
15000 J
A 0.5 kg pendulum at the bottom of its swing is going 3 m/s. What is its kinetic energy?
2.3 J
An Olympic curler delivers a stone with an initial speed of 4.4 m/s. The stone has a mass of 20.0 kg. The coefficient of friction between the stone and the ice is 0.030. Assume the acceleration of gravity is 9.81 m/s/s. What is the distance that the stone will travel before it comes to a complete stop?
32 M
A 20-kg cart rolling down a ramp at 2 meters per second has ____ joules of kinetic energy.
40
In women's fastpitch softball, the pitcher throws the ball at 30.0 m/s. The ball has a mass of 1.08 kg. What is the kinetic energy of the softball?
486 J
Ball A has triple the mass and speed of Ball B. What is the ratio of the kinetic energy of Ball A to Ball B?
9
What is the gravitational potential energy of a 1.0 kg mass 1.0 m above the ground?
9.8 J
As you may recall, momentum (p) is computed as the product of mass and velocity (mv). Using your knowledge of algebra, answer the following question: Which equation correctly defines kinetic energy in terms of momentum? (Recall that KE = 0.5mv2)
KE=0.5pv
The equation for kinetic energy:
KE=1/2mv^2
Objects in motion have?
Kinetic Energy because of mass and speed.
A free-falling skydiver is converting gravitational potential energy into the kinetic energy of motion.
True
Which of the following is a valid way to determine the spring constant, k?
With a position of known potential energy, measure the distance away from relaxed, and calculate.
Gravitational potential energy is always measured in relation to
a zero level
spring constant
an expression of the ratio of force to displacement for a spring or other elastic material
Which of the following is NOT involved in the flight of a tennis ball during a tennis match?
chemical potential energy
Two cars of equal mass, moving at different speeds along a road, will have
different kinetic energy
A pocket watch contains a long, spiral piece of metal which is coiled tightly as the watch is wound. What form of potential energy is involved in winding a pocket watch?
elastic potential energy
The energy of movement, which is calculated by 0.5mv2, is
kinetic energy
The main difference between kinetic and potential energy is that
kinetic energy involves motion, and potential energy involves position.
A k value of 110 for a spring indicates that the spring would require _____force to stretch than for a spring with a k value of 66.
more
The stress that builds up along a fault line is a form of
potential energy
The terms, 0.5mvf2 - 0.5mvfi2, are the same thing as
the change in kinetic energy
The work-kinetic energy theorem states that the total work done on an object is equal to
the change in kinetic energy of the object
elastic potential energy
the energy available for use when an elastic body returns to its original configuration
Kinetic Energy
the energy of an object that is due to the object's motion
potential energy
the energy that an object has because of the position, shape, or condition of the object
When a hammer strikes a nail, the work done on the hammer contains a negative sign, indicating that
the hammer loses kinetic energy
If friction is the only force acting on an object during a given physical process, which of the following assumptions can be made in regard to the object's kinetic energy?
the kinetic energy decreases
gravitational potential energy
the potential energy stored in the gravitational fields of interacting bodies
The potential energy of a position of a spring depends on two factors,
the springs constant and the distance away from the relaxed position of the spring
work-kinetic energy theorem
the theorem that states that the change in kinetic energy of a moving particle is equal to the work done by all of the forces acting on the particle
