An object is projected from the ground with an initial velocity v0 at an angle w
ID: 1494846 • Letter: A
Question
An object is projected from the ground with an initial velocity v0 at an angle with respect to the horizontal. How would the horizontal and vertical displacements and velocities, acceleration, momentum, work, kinetic and potential energies change as a result of the object’s path of movement?
Consult the diagram below & use the most appropriate word to complete the essay.
Words to use: Maximum Minimum Zero Increases Decreases Positive Negative Stays the same Constant Conservation of energy Downwards Parabolic
Complete the statements below by filling in the blanks with the best appropriate word.
An object is projected from the ground up into the air at an angle with respect to the horizontal. At the very instant that object is fired, the object’s velocity is _______________, its momentum is _______________ and its kinetic energy is _______________ As the projectile leaves the ground and travels along a _______________ path, both the vertical and horizontal displacements _______________. As it rises, the vertical component of the velocity _______________ because the acceleration is directed _______________ at a constant 9.80 m/s2 and the horizontal component of the velocity remains _______________. Also as it rises, the kinetic energy _______________ and the potential energy _______________ by the law of _______________. Ignoring air resistance, the only force acting on the projectile is its _______________ that acts _______________ Since the projectile is rising, the weight does _______________ work. At the top of its path, the projectile has stopped rising but is still moving horizontally. Consequently, the vertical displacement is _______________, the vertical component of the velocity is _______________, the horizontal component of the velocity remains _______________, and the acceleration directed _______________ at a constant 9.80 m/s2. As a result, the momentum is _______________ , the potential energy is _______________ and the kinetic energy is _______________ . The work is being done on the projectile at this time is _______________. As the projectile begins to fall towards the target on the ground, the vertical component of the velocity _______________ because the acceleration is directed _______________ at a constant 9.80 m/s2 and the horizontal component of the velocity remains _______________. As it falls, the kinetic energy _______________ and the potential energy _______________ by the law of _______________. Ignoring air resistance, the only force acting on the projectile is its _______________ that acts downwards. Since the projectile is falling, the weight does _______________ work.
Explanation / Answer
An object is projected from the ground up into the air at an angle with respect to the horizontal. At the very instant that object is fired, the object’s velocity is _maximum, its momentum is _maximum and its kinetic energy is maximum As the projectile leaves the ground and travels along a parabolic path, both the vertical and horizontal displacements increases. As it rises, the vertical component of the velocity decreases because the acceleration is directed downwards at a constant 9.80 m/s2 and the horizontal component of the velocity remains constant. Also as it rises, the kinetic energy decreases and the potential energy increases by the law of conservation of energy. Ignoring air resistance, the only force acting on the projectile is its weight that acts downwards Since the projectile is rising, the weight does negative work. At the top of its path, the projectile has stopped rising but is still moving horizontally. Consequently, the vertical displacement is maximum , the vertical component of the velocity is zero , the horizontal component of the velocity remains constant, and the acceleration directed downwards at a constant 9.80 m/s2. As a result, the momentum is mimimum , the potential energy is maximum and the kinetic energy is mimimum . The work is being done on the projectile at this time is zero . As the projectile begins to fall towards the target on the ground, the vertical component of the velocity increses because the acceleration is directed downwards at a constant 9.80 m/s2 and the horizontal component of the velocity remains constant. As it falls, the kinetic energy increases and the potential energy decreases by the law of conservation of energy. Ignoring air resistance, the only force acting on the projectile is its weight that acts downwards. Since the projectile is falling, the weight does positive work.