Work, Energy, and Power in Physics
What happens to total mechanical-energy when air resistance acts on a falling parachuter descending with constant velocity?
Decrease-in-kinetic-and-gravitational-potential-energy-as-lost-to-air-resistance
Increase-in-gravitational-potential-energy-as-falling-object-slows-down
No change occurs in total mechanical-energy as gravitational-potential converts entirely into thermal-energy-due-to-air-resistance
Kinetic-energy-is-transferred-to-the-surrounding-air-particles-increasing-their-mechanical-energy
In a perfectly elastic collision scenario of two objects of mass and with initially stationary, what is the ratio of final speed to the final speed after said collision?
A ball rolls up a hill without friction; at what point will its kinetic and potential energies be equal?
At no point; only total mechanical energy remains constant.
Halfway up the hill.
When its speed is reduced by half from that at the bottom.
At the top of the hill where it comes to rest for an instant.
If a pendulum with length swings from an initial angle with negligible air resistance, what approximation can affect calculating its period most significantly?
Neglecting Earth's rotation effect on pendulum motion for moderate latitudes
Considering string mass in tension calculations when it's negligible
Assuming simple harmonic motion for large
Ignoring variation in with altitude for pendulums on tall buildings
How does increasing an object's speed affect its momentum if mass stays constant?
The change in momentum depends on a square root relationship between speed and velocity().
Momentum doubles every time when velocity doubles().
It doesn't affect momentum as long as gravity remains unchanged().
Momentum increases linearly with speed since ().
If a projectile is launched from the ground at an angle above the horizontal, which theoretical adjustment to its kinetic energy equation would best account for air resistance progressively slowing it down?
Periodic exchange between greater potential and lesser kinetic energies reflecting oscillatory motion.
Decrease in both potential and kinetic energies due to conversion of mechanical energy into thermal energy.
Constant mechanical energy as air resistance does work equal to the work by gravitational forces.
Increase in potential energy is less than the decrease in kinetic energy due to work done against air resistance.
What is impossible to calculate using a conservation energy principle, if the body in question is undergoing simple harmonic oscillations?
Gravitational potential energy at a particular point
Total mechanical energy at the start of the oscillation cycle
Kinetic energy at a turning point
Potential energy stored in the oscillating spring

How are we doing?
Give us your feedback and let us know how we can improve
A rotating solid disk experiences angular deceleration due to magnetic braking; what effect arises from combining Maxwell's laws with Newtonian mechanics?
Electromagnetic eddy currents opposing rotation manifest additional torque resisting motion.
Spin-orbit coupling aligns magnetic dipoles decreasing net magnetization resultant loss rates.
Magnetic fields penetrate reducing rotational inertia modifying angular velocity proportionately.
Lorentz forces induce charge separation shifting center mass adjusting precession dynamics accordingly.
If two identical masses attached to springs with different constants and displaced by the same amount from equilibrium points, will they have equal kinetic energies when they reach the equilibrium point?
Yes, but only if the springs are compressed instead of extended.
No, kinetic energy is only dependent on the mass and displacement, not the stiffness of the spring.
Yes, the displacement is both the same and the masses are identical, so their kinetic energies should be equal.
No, the mass attached to the stiffer spring will have less kinetic energy because the force required to compress it is greater.
How does increasing temperature influence the total mechanical energy in a macroscopic pendulum swinging through air?
It creates convective currents that add external work onto the pendulum system inconsistently per cycle.
Increased air viscosity from higher temperatures can enhance dissipative losses incrementally over time.
It induces thermal expansion altering pendulum length and thus its potential energy at peak swing height.
Higher temperature produces increased molecular vibrations that can amplify existing motions via resonance effects intermittently during cycles.