I think you're fishing for "temporary magnet" or something like that,
but I don't agree with it.
Credit card strips, refrigerator magnets, recording tape, bar magnets,
and big heavy horseshoe magnets are permanent magnets ... you don't
have to keep an electric current circulating around them to make them
magnetic.
But that doesn't mean that they stay magnetic no matter WHAT you do
to them. They can be DEmagnetized by being heated, dropped on the
floor, hit with a hammer, or in the presence of another, stronger magnet.
<span>The change in internal energy is only gravitional PE because the tube is being drug up at a constant speed. Since it is at a constant speed, the change in KE is 0.
Change in PE = m*g*h = 78 kg * 10 m/s^2 * 30 m = 23400 J
Work done on the system is from the force
Work = force * distance = 350 N * 120 m = 42000 J
So, work added 42000 J to the system, but the rider's energy only increased 23400 J. Therefore, friction took up the difference. Friction is where the thermal energy comes from
Q = 42000 J - 23400 J = 18600 J.
Therfore, friction generated 18600 J of heat to the surroundings.</span>
Explanation:
(a) Draw a free body diagram of the cylinder at the top of the loop. At the minimum speed, the normal force is 0, so the only force is weight pulling down.
Sum of forces in the centripetal direction:
∑F = ma
mg = mv²/RL
v = √(g RL)
(b) Energy is conserved.
EE = KE + RE + PE
½ kd² = ½ mv² + ½ Iω² + mgh
kd² = mv² + Iω² + 2mgh
kd² = mv² + (m RC²) ω² + 2mg (2 RL)
kd² = mv² + m RC²ω² + 4mg RL
kd² = mv² + mv² + 4mg RL
kd² = 2mv² + 4mg RL
kd² = 2m (v² + 2g RL)
d² = 2m (v² + 2g RL) / k
d = √[2m (v² + 2g RL) / k]
Answer:
A police radar gun uses X-band microwave radiation at a frequency of 13.1 GHz. Microwaves travel at the speed of light, or 3x108 m/s. Since the frequency shift will be small for practical car speeds and difficult to detect, the shifted frequency is compared to the original frequency, and the resulting beat frequency is used to determine the speed of the car.
a.) If Michael is traveling at 29 m/s, what is the resulting beat frequency that the radar gun detects?
ANSWER: 2533 Hz
Explanation:
Answer:
The acceleration of the object is 
Explanation:
Given:
Initial velocity of object 
= 200 feet/second
Final velocity of object 
= 50 feet/second
Time of travel = 5 seconds
To calculate acceleration of the object we will find the rate of change of velocity with respect to time.
So, acceleration 
is given by:
where represents final velocity, represents initial velocity and 
is time of travel.
Plugging in values to evaluate acceleration.
The acceleration of the object is (Answer). The negative sign shows the object is slowing down.
