Fundamentals 3 Flashcards
Write the equation for kinetic energy.
KE = (1/2)mv^2
In what kind of collision is linear momentum conserved?
all collisions. (Because no external force acts on the two objects in the collision, just the internal force of one object on the other.)
In what kind of collision is mechanical energy conserved?
elastic.
When a planet makes a circular orbit around a sun, say or show briefly how to solve for the planet’s orbital speed.
Set the gravitational force equation equal to ma, where a is v^2/r.
Write the equation for the gravitational field at the surface of a planet.
g = GM/r^2.
A motor cart in the laboratory can be set to move at any steady velocity. A student sets the cart into motion at many different steady velocities, each time measuring the distance the car travels in 5.0 seconds. The student graphs this distance on the vertical axis, and the cart’s velocity on the horizontal axis.
If this graph is a curve, what could be graphed instead to get a straight line? If this graph is a line, what is the physical meaning of the slope?
The y-axis is d, the x-axis is v. So what’s multiplying the x-axis variable is the slope - that’s t. The slope should be the time the cart spent in each trial, i.e. 5 seconds.
A motor cart in the laboratory can be set to move at any steady velocity. A student sets the cart into motion at many different steady velocities, each time measuring the distance the car travels in 5.0 seconds. The student graphs this distance on the vertical axis, and the cart’s velocity on the horizontal axis.
Is this graph a line or a curve? Briefly, why?
Line - the equation for steady speed is d=vt. So d is linear with v - no squares or square roots or denominators.
On a velocity-time graph, how do you determine the position of an object?
You can’t. (The displacement is the area under the v-t graph, but the position is undeterminable.)
Write the equation for the potential energy of a spring
SPE = (1/2)kx^2.
Write the equation for the force of a spring.
F = kx.
