Kinetic energy and velocity are at zero when the magnets are held apart, and both increase rapidly when they are released and move together. Energy stored in the magnetic field decreases.
Answer:
<em>The stopping distance if the car skids is 225 ft</em>
Explanation:
<u>Friction</u>
It's a force that opposes movement and requires the interaction of two surfaces. If the interaction occurs from relative rest, then the friction force is greater than the case where the interactions occur from relative speed. The static coefficient is greater than the kinetic friction, and the relation is
If the car needs 180 ft to stop with slipping impending (no relative speed between the tires and the road), we can find the distance needed to stop the car in skidding conditions, which we expect to be greater.
This indicates that the friction forces have the same relation
Since the mass is the same:
Simplifying
Now we'll focus on the dynamic formulas. The acceleration can be computed from the initial speed vo, the final speed vf and the distance x:
This relation stands for both accelerations, which happen to be decelerations:
Where xk and xs are the distances needed to stop the car in each case. Note that vf and vo are the same since the test is done with the same values for both. Knowing the relation between the accelerations, we can have the relationship between the distances
Simplifying
Thus
Electrostatic forces are non-contact forces; they pull or push on objects without touching them
Answer:
a=-1.58 m/s^2
Explanation:
Vo=34m/s
Vf=15m/s
t=12s
a= dV/dt = (Vf-Vo) /t = (15-34)/12
= - 19/12 = - 1.58m/s2