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borishaifa [10]
3 years ago
8

A 30-kg child sits at the top of a 3-meter slide. After sliding down, the child is traveling 4 m/s. How much PE does he start wi

th? How much KE does he end with? How much energy is lost to friction?
Physics
1 answer:
Jobisdone [24]3 years ago
6 0
At the top:

         Potential Energy = (mass) x (gravity) x (height)

                                       = (30 kg) x (9.8 m/s²) x (3 meters)

                                       =      882 joules

At the bottom:

           Kinetic Energy  =  (1/2) x (mass) x (speed)²

                                       = (1/2) x (30 kg) x (3 m/s)²

                                       =        (15 kg)  x  (9 m²/s²)

                                       =              135 joules .

He had  882 joules of potential energy at the top,
but only  135 joules of kinetic energy at the bottom.

Friction stole  (882 - 135) = 747 joules of his energy while he slid down.
The seat of his jeans must be pretty warm.
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Zinaida [17]

Answer:the  maximum Hall voltage across the strip= 0.00168 V.

Explanation:

The Hall Voltage is calculated using

Vh= B x v x  w

Where

B is the magnitude of the magnetic field, 5.6 T

v is the speed/  velocity of the strip, = 25 cm/s  to m/s becomes 25/100=0.25m/s

and w is the width of the strip=  1.2 mm to meters becomes 1.2 mm /1000= 0.0012m

 Solving

Vh= 5.6T x 0.25m/s x 0.0012m

=0.00168T.m²/s

=0.00168Wb/s

=0.00168V

Therefore, the  maximum Hall voltage across the strip=0.00168V

3 0
3 years ago
What is the momentum of a .005kg bumble bee that is traveling at a velocity of 3.0m/s?
stiks02 [169]

p=mv

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4 0
3 years ago
Assume that the speed of light in a vacuum has the hypothetical value of 18.0 m/s. A car is moving at a constant speed of 14.0 m
denis23 [38]

Answer:

4.245s

Explanation:

Given that,

Hypothetical value of speed of light in a vacuum is 18 m/s

Speed of the car, 14 m/s

Time given is 6.76 s, and we're asked to find the observed time, T

The relationship between the two times can be given as

T = t / √[1 - (v²/c²)]

The missing variable were looking for is t, and we can find it if we rearrange the formula and make t the subject

t = T / √[1 - (v²/c²)]

And now, we substitute the values and insert into the equation

t = 6.76 * √[1 - (14²/18²)]

t = 6.76 * √[1 - (196/324)]

t = 6.76 * √(1 - 0.605)

t = 6.76 * √0.395

t = 6.76 * 0.628

t = 4.245 s

Therefore, the time the driver measures for the trip is 4.245s

8 0
3 years ago
Referring to the above diagram, how high will the ball rise on the right-hand incline?
Marina CMI [18]
I think it’s 15cm
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3 0
4 years ago
What is the anomalous expansivity of water
lora16 [44]

Answer:

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Explanation:do you want me to explain it more??

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