All categories

3 years ago

As a car comes to a skidding stop, what happens to the car’s energy

Physics

1 answer:

Vladimir79 [104]3 years ago

5 0

The answer is 3. Internal energy decrease

You might be interested in

Sound travels at a rate of 340 m/s in all directions through air. Matt rings a very loud bell at one location, and Steve hears i

Vika [28.1K]

Answer:

110 m/s

Explanation:

because if you subtract 450 from 340 you get 110

6 0

2 years ago

The established value for the speed of light in a vacuum is 299,792,458 m/s. What is the order-of-magnitude of this number?

iogann1982 [59]

The order of magnitude is 10⁸ .

6 0

3 years ago

A rock falls off a cliff. How fast will it be going after falling for 4.33 seconds?

bixtya [17]

Answer:42.43m/s

Explanation:According to vf=vi+at, we can calculate it since v0 equals to 0. vf=0+9.8m/s^2*4.33s= 42.434m/s

4 0

1 year ago

A certain heat engine takes in 300 J of energy from a hot source and then transfers 200 J of that energy to a colder object. Wha

Greeley [361]

Answer:

The efficiency is 0.33, or 33%.

Explanation:

From the thermodynamics equations, we know that the formula for the efficiency of a heat engine is:

$\eta=1-\frac{Q_2}{Q_1}$

Where η is the efficiency of the engine, Q_1 is the heat energy taken from the hot source and Q_2 is the heat energy given to the cold object. So, plugging the given values in the formula, we obtain:

$\eta=1-\frac{200J}{300J}=0.33$

This means that the efficiency of the heat engine is 0.33, or 33% (The efficiency of an engine is dimensionless).

5 0

3 years ago

An Atwood machine is constructed using a hoop with spokes of negligible mass. The 2.3 kg mass of the pulley is concentrated on i

Sergeu [11.5K]

Answer:

$a = 2.77~{\rm m/s^2}$

Explanation:

Since the pulley has a mass concentrated on its rim, the pulley can be considered as a ring.

The moment of inertia of a ring is

$I = mr^2 = (2.3)(23.5\times 10^{-2})^2 = 0.127$

The mass on the left is heavier, that is the pulley is rotating counterclockwise.

By Newton's Second Law, the net torque is equal to moment of inertia times angular acceleration.

$\tau = I \alpha$

Here, the net torque is the sum of the weight on the left and the weight on the right.

$\tau = m_1gR - m_2gR = (1.65)(9.8)(23.5\times 10^{-2}) - (1)(9.8)(23.5\times 10^{-2}) = 1.497~{\rm Nm}$

Applying Newton's Second Law gives the angular acceleration

$\tau = I\alpha\\1.497 = 0.127\alpha\\\alpha = 11.78~{\rm rad/s^2}$

The relation between angular acceleration and linear acceleration is

$a = \alpha R$

Then, the linear acceleration of the masses is

$a = 11.78 \times 23.5\times 10^{-2} = 2.77~{\rm m/s^2}$

5 0

3 years ago