# Tagged Questions

The description of the movement of bodies by their position, velocity, acceleration (and possibly higher time derivatives, such as, jerk) without concern for the underlying dynamics/forces/causes.

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### Does the physical cross section of a projectile have an effect on the motion of a target? [closed]

Why can a baseball (moving with kinetic energy) move a baseball glove (or how a hammer displaces a nail),. yet a bullet can't move a person? I know the laws of conservation of energy, deformation, etc....
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### Instantaneous Velocity after bouncing off a wall

I have a ball, and I throw it at a wall as a projectile (assume that the ball's position the instant the journey begins is on level-ground). The ball hits the wall with a velocity that is at right ...
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### What decides distribution of momenta and energy in rigid collisions?

I recall in Highschool physics receiving a problem of the form "assume 2 spherical bodies" $P_1, P_2$ enter a collision where $P_1$ has momentum $m_1 V_1$ and $P_2$ has momentum $m_2 V_2$, both ...
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### Direction of motion 1 [closed]

A man on a bike travelling east on straight road at 8km/h sees a car driving north at 60km/h. What is the apparent speed and diretion of motion of car to the cyclist?
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### What will happen if you move a photon move in a straight line with no oscillations? [closed]

As light is a wave, it travels in an oscillating pattern: | _ _ _ _ _ _ _ _ |/_\ _ /_\___/_\ _ /_\___/_\ _ /_\___/_\ _ /_\___ | \_/ \_/ \_/ \_/ \_/ \_/ ...
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### Impulse Equations

A solid sphere of mass $m$ rolls without slipping on a horizontal surface and collides with a vertical wall, elastically. The coefficient of friction between the sphere and wall is $\mu$. After the ...
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### Impact Speed of a car

A car (Mass 4500 Kg) hits a concrete Block (1000 Kg) on left edge. After impact, block rotates in circular motion and stops at about 24 feet from its initial position. How to calculate force with ...
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### Free Fall Motion in Physics [closed]

A man in a close elevator with no floor indicator,does not know whether the elevator is stationary, moving upward or moving downward at a constant velocity. To try to find out, the person drops a coin ...
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### Velocity of an object rolling down a spiral

Imagine a fiction less spring-like spiral, an object will roll down the wire path the spring creates. From conservation of energy, the initial PE will be equivalent to gravitational potential energy, ...
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### Maximize time of flight and range at the same time in projectile motion

Given the equations of projectile motion (no air resistance), it is easy to find the launching angle theta that produces the maximum range. That angle is 45 degrees. The maximum time of flight is ...
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### Would this be correct for kinetic energy in special relativity?

In galilean relativity $$p=mv$$ and $$KE=\frac{1}{2}mv^2$$ If I understand it in special relativity the equation for momentum is $$p=\frac{mv}{\sqrt{1-\frac{v^2}{c^2}}}$$ In galilean relativity ...
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### Vector Navigation and equations [closed]

So I am taking a grade 12 physics online course and I am getting stuck on the Vector Navigation equations as there isn't much explanation in my course. The following text is found in my online course....
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### Why do I get inconsistent answers with the kinematics equations?

The initial velocity is 14 m/s the final velocity is 0. The distance is 9.0 m and the time is 1.5 s. When solving for the acceleration, why do I get different values when using different kinematic ...
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### Why are my answers wrong for braking distances? [closed]

I have been working on a presentation to find the braking distances at the velocities of cars obeying speed limits for a range of common speed limits. I'm working with the equation d= \frac{v^2}{...
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### Projectiles ability to do work to a box when connected by string? [closed]

I was wondering, the work-energy theorem states that KE can do work, as it is Mechanical energy. if the KE energy and thus Mechanical energy of a ball, if external...can do work on an object, ...
I have a physics problem related to projectile motion, I am having difficulties figuring out how to find the initial speed in the $x$ and $y$ directions, as well of the height of the drop. I've tried ...