All categories

3 years ago

Using the formula 1/2 (m x v2), what is the kinetic energy of a 4 kg rock falling through the air at 5 m/s

Physics

1 answer:

aivan3 [116]3 years ago

5 0

Answer:

KE = 50J

Explanation:

$KE = \frac{1}{2}mv^{2} \\\\ KE = \frac{1}{2}(4)(5)^{2} \\\\ KE = 2(25) \\\\ KE = 50J$

You might be interested in

Diamond has an index of refraction of 2.419. What is the critical angle for internal reflection inside a diamond that is in air?

SSSSS [86.1K]

Answer:

C) 24.4°

Explanation:

let nd = 2.419 be the index of refraction of diamond and na = 1.0 be the index of refraction of air and ∅c be the critical angle.

according to Snell's Law:

sin(∅c) = na/nd

sin(∅c) = (1.0)/(2.419)

∅c = 24.4°

4 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

How many significant figures are in 50.5?

Art [367]

3 as a single number is considered a sf

7 0

3 years ago

1. Water boils at 100°C at sea level. If the water in this experiment did not boil at 100°C, what could be the reason?

umka2103 [35]

Answer:

It may not be at the sea level

Explanation:

The reason here is water only boils at sea level. This means that if you move water to a different height, say top of a mountain, the boiling temperature of water would change. This is due to the pressure drop at high place. The drop of pressure would make it harder to transform water liquid to gas, thus requiring more temperature.

8 0

3 years ago

Read 2 more answers

Waht scientific name of a horse is Equus callabux what is the genus name of the horse

Zarrin [17]

Answer:

middle

Explanation:

4 0

3 years ago