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2 years ago

Thermal energy transfers from a cup of tea at 350 K to the hand holding it. A)True B)False

Physics

1 answer:

Alexandra [31]2 years ago

6 0

Answer:

true

Explanation:

it is an energy transfer

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A friend throws a coin into a pool. you close your eyes and dive toward the spot where you saw it from the edge of the pool. whe

madreJ [45]

The Correct Answer Is A

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2 years ago

Read 2 more answers

When turned on, a fan requires 5.0 seconds to get up to its final operating rotational speed of 1200 rpm. a) How large is the fi

vova2212 [387]

Answer:

125.6 rad/s

25.12 rad/s²

Explanation:

t = time required by the fan to get up to final operating speed = 5 sec

w = final operating rotational speed = 1200 rpm

we know that :

1 revolution = 2π rad

1 min = 60 sec

w = $1200\frac{rev}{min}\frac{2\pi rad}{1 rev}\frac{1 min}{60 sec}$

w = $\frac{1200\times 2\pi }{60}\frac{rad}{s}$

w = 125.6 rad/s

w₀ = initial angular speed = 0 rad/s

α = angular acceleration

using the equation

w = w₀ + α t

125.6 = 0 + α (5)

α = 25.12 rad/s²

5 0

2 years ago

A student conducts an experiment in which a cart is pulled by a variable applied force during a 2sec time interval. In trial 1,

Harlamova29_29 [7]

Answer:

change of momentum does not depend on the mass of the cars, as the force and time are the same all vehicles have the same change of momentum

Explanation:

Let's look for the speed of the car

F = m a

a = F / m

We use kinematics to find lips

v = v₀ + a t

v = v₀ + (F / m) t

The moment is defined by

p = m v

The moment change

Δp = m v - m v₀

Let's replace the speeds in this equation

Δp = m (v₀ + F / m t) - m v₀

Δp = m v₀ + F t - m v₀

Δp = F t

We see that the change of momentum does not depend on the mass of the cars, as the force and time are the same all vehicles have the same change of momentum

8 0

2 years ago

Which is harder, air tight or water tight seals?

Vladimir [108]

Should be an air tight seal

4 0

2 years ago

At what wavelength would a star radiate the greatest amount of energy if the star has a surface temperature of 60,000 K?

kompoz [17]

Answer:

$\lambda=4.81\times 10^{-8}\ m$

Explanation:

We have,

The surface temperature of the star is 60,000 K

It is required to find the wavelength of a star that radiated greatest amount of energy. Wein's displacement law gives the relation between wavelength and temperature such that :

$\lambda T=2.89\times 10^{-3}$

Here,

$\lambda$ = wavelength

$\lambda=\dfrac{2.89\times 10^{-3}}{60000}\\\\\lambda=4.81\times 10^{-8}\ m$

So, the wavelength of the star is $4.81\times 10^{-8}\ m$ .

7 0

2 years ago