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3 years ago

Why is heat produced when we rub our hands together

Physics

2 answers:

vladimir1956 [14]3 years ago

6 0

Answer:

heat is produced by rubbing our hands together which cause friction and during the process you can feel heat.

kakasveta [241]3 years ago

5 0

Answer:

friction

the rubbing of the surfaces create friction, giving off heat

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When one object pushes or pulls another object, the first object is________________________ a force on the second object.

Arlecino [84]

The answer is inertia

5 0

3 years ago

A 0.676 m long section of cable carrying current to a car starter motor makes an angle of 57.7º with the Earth’s 5.29 x 10^−5T f

Studentka2010 [4]

Answer:

The current in the wire under the influence of the force is 216.033 A

Solution:

According to the question:

Length of the wire, l = 0.676 m

$\theta = 57.7^{\circ}$

Magnetic field of the Earth, $B_{E} = 5.29\times 10^{- 5} T$

Forces experienced by the wire, $F_{m} = 6.53\times 10^{-3} N$

Also, we know that the force in a magnetic field is given by:

$F_{m} = IB_{E}lsin\theta$

$I = \frac{F_{m}}{B_{E}lsin\theta}$

$I = \frac{6.53\times 10^{-3}}{5.29\times 10^{- 5}\times 0.676sin57.7^{\circ}$

I = 216.033 A

5 0

3 years ago

Suppose a star the size of our Sun, but with mass 9.0 times as great, were rotating at a speed of 1.0 revolution every 7.0 days.

kvasek [131]

Answer:

Its rotation will be 3.89x10⁴ rad/s.

Explanation:

We can find the rotation speed by conservation of the angular momentum:

$L_{i} = L_{f}$

$I_{i}\omega_{i} = I_{f}\omega_{f}$ (1)

The initial angular speed is:

$\omega_{i} = \frac{1 rev}{7 d} = 0.14 \frac{rev}{d}$

The moment of inertia (I) of a sphere is:

$I = \frac{2}{5}mr^{2}$ (2)

Where m is 9 times the sun's mass and r is the sun's radius

By entering equation (2) into (1) we have:

$\frac{2}{5}m_{i}r_{i}^{2}\omega_{i} = \frac{2}{5}m_{f}r_{f}^{2}\omega_{f}$

$9m_{sun}(696342 km)^{2}0.14\frac{rev}{d} = \frac{3}{4}9m_{sun}(13 km)^{2}\omega_{f}$

$\omega_{f} = \frac{4}{3}*0.14 \frac{rev}{d}(\frac{696342 km}{13 km})^{2} = 5.36 \cdot 10^{8} \frac{rev}{d}*\frac{1 d}{24 h}*\frac{1 h}{3600 s}*\frac{2\pi rad}{1 rev} = 3.89 \cdot 10^{4} rad/s$

Hence, its rotation will be 3.89x10⁴ rad/s.

I hope it helps you!

3 0

4 years ago

A spaceship travels at a constant speed from earth to a planet orbiting another star. When the spacecraft arrives, 12 years have

tigry1 [53]

Answer:

$7.2878\times10^{16} m$

Explanation:

Time elapsed on Earth $d_{t}$ = 12 years

Time elapsed on board the ship $d_{t_o}$ = 9.2 years

now r= $\frac{d_{t} }{d_t_o}$ = 12/9.2= 1.3043

$v= c \sqrt{1-\frac{1}{r^2}}$

$v= 3\times10^8 \sqrt{1-\frac{1}{1.3043^2}}$

v= $1.9258\times10^8$

therefore distance L= $d_{t}\times v$

putting value we get

= $12\times\times1.9258\times10^8$

= $12\times\times365\times24\times3600\times1.9258\times10^8$

= $7.2878\times10^{16} m$

4 0

3 years ago

9. You drive a car from Milwaukee to Chicago, which is a distance of 150km and it takes you 95

Katena32 [7]

For this case we have to, by definition:

$v = \frac {x} {t}$

Where:

v: It's the velocity

x: It is the distance traveled

t: It is the time spent

1 hour equals 60 minutes and 1 minute equals 60 seconds.

On the other hand:

1 kilometer equals 1000 meters

So: $\frac {150} {95} \frac{km} {min} * \frac {1} {60} \frac {min} {sec} * \frac {1000} {1} \frac {m} {km} = \frac {150 * 1000} {95 * 60} \frac {m} {sec} = \frac {15000} {5700} \frac {m} {sec} = 2.63 \frac {m} {sec}$

On the other hand: $\frac {150} {95} \frac{km} {min} * \frac {60} {1} \frac {min} {hr} = \frac {150 * 60} {95} \frac {km} {h} = 94.74 \frac {km} {h}$

ANswer:

$2.63 \frac {m} {sec}\\94.74 \frac {km} {h}$

8 0

4 years ago

Why is heat produced when we rub our hands together ​

Why is heat produced when we rub our hands together