What is the conservation of energy?

Describe how radio waves are different from sound waves.

Lilit [14]

Answer:

sound and radio waves are completely different phenomena.

Explanation:

7 0

2 years ago

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A student wants to determine the impulse delivered to the lab cart when it runs into the wall. The student measures the mass of

WINSTONCH [101]

The correct answer to the question is : A) The velocity of the cart after it hits the wall.

EXPLANATION:

Before answering this question, first we have to understand impulse.

Impulse of a body is defined as the change in momentum or the product of force with time.

Mathematically impulse = m ( v- u ).

Here, v is the final momentum and u is the initial momentum.

Hence, we need the velocity of the cart after it hits the wall in order to calculate the impulse of the lab cart.

4 0

3 years ago

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Suppose that a spring with a larger spring constant was used in this same apparatus. If a given mass were rotated at the same ra

malfutka [58]

Answer:

The new period of rotation using the new spring would be less than the period of rotation using the original spring

Explanation:

Generally the period of rotation of the mass is mathematically represented as

$T = 2 \pi \sqrt{\frac{I}{k} }$

Here I is the moment of inertia of the mass about the rotation axis and k is the spring constant

Now looking at the equation we can tell that T is inversely proportional to the square root of the spring constant which means that for a larger spring constant the time period would be lesser

6 0

3 years ago

Two 84.5 g ice cubes are dropped into 30 g of water in a glass. If the water is initially at a temperature of 50 C and if the ic

Setler [38]

Answer:

final temperature will be 0 degree C

Total amount of ice will be

$m_{ice} = 182 g$

total amount of water

$m_{water} = 17 g$

Explanation:

After thermal equilibrium is achieved we can say that

Heat given by water = heat absorbed by ice cubes

so we will have

Heat given by water to reach 0 degree C

$Q_1 = m_1s_1 \Delta T_1$

$Q_1 = 0.030(4186)(50 - 0)$

$Q_1 = 6279 J$

heat absorbed by ice cubes to reach 0 degree

$Q_2 = m_2 s_2 \Delta T_2$

$Q_2 = (0.169)(2100)(30)$

$Q_2 = 10647 J$

so we will have

$Q_2 > Q_1$

so here we can say that few amount of water will freeze here to balance the heat

$10647 - 6279 = mL$

$m = \frac{10647 - 6279}{335000}$

$m = 13 g$

so final temperature will be 0 degree C

Total amount of ice will be

$m_{ice} = 84.5 + 84.5 + 13$

$m_{ice} = 182 g$

total amount of water

$m_{water} = 30 - 13$

$m_{water} = 17 g$

4 0

3 years ago

An elevator accelerates upward at 1.2 m/s 2 . the acceleration of gravity is 9.8 m/s 2 . what is the upward force exerted by the

Marysya12 [62]

We can find the force by using the following formula;
N = ma + mg
Fa = ma = 76 x 1.2 = 91.2
Fg = mg = 76 x 9.8 = 744.8
N = 91.2 + 744.8 = 836
So, the force is 836 N.

8 0

3 years ago