All categories

3 years ago

Hunter’s velocity was 4.5 m/s. At the end of his race, his velocity was the same. Which best describes his movement?

Chemistry

2 answers:

pogonyaev3 years ago

5 0

If an object is not changing its velocity, then the object is not accelerating. (There’s no acceleration)

Debora [2.8K]3 years ago

3 0

Answer:

His movement stopped

Explanation:

You might be interested in

In the winter, a heated home in the Northeast might be maintained at a temperature of 78°F. What is this temperature on the Cels

masya89 [10]

Answer: $25.6^0C$ , $298.6K$

Explanation:

Temperature of the gas is defined as the degree of hotness or coldness of a body. It is expressed in units like $^0C$ and $K$

These units of temperature are inter convertible.

We are given:

Temperature of the gas = $78^0F$

Converting this unit of temperature into $^0C$ by using conversion factor:

$^oC=\frac{5}{9}\times (^oF-32)$

$^0C=\frac{5}{9}\times (78^oF-32)$

$25.6^0C$

Converting this unit of temperature into $K$ by using conversion factor:

$K=t^0C+273$

$K=25.6+273$

$298.6K$

Thus the temperature on the Celsius and Kelvin scales are $25.6^0C$ and $298.6K$ respectively.

6 0

3 years ago

How many joules of energy are made by the loss of 100kg of mass using the formula E=mc2? please help!!!

asambeis [7]

Answer:

E = 3 × 10¹⁰ J

Explanation:

Mass, m = 100 kg

We need to find energy made by the loss of 100 kg of mass. The formula between the mass and energy is given by :

E = mc²

Where c is speed of light

Putting all the values, we get :

E = 100 kg × (3×10⁸ m/s)²

= 3 × 10¹⁰ J

So, the required energy is 3 × 10¹⁰ J.

6 0

2 years ago

Question 3(1 point)

SVETLANKA909090 [29]

Answer:

Group 8 is a group (column) of chemical elements in the periodic table. It consists of iron (Fe), ruthenium (Ru), osmium (Os) and hassium (Hs). They are all transition metals.

Explanation:

5 0

2 years ago

1 One mole of an element contains which of the following?

lozanna [386]

Answer:

1) B 2) both a and c

5 0

2 years ago

How many kilojoules of energy would be required to heat a 225g block of aluminum from 23.0 C to 73.5 C?

gulaghasi [49]

Answer:

$\boxed {\boxed {\sf 10.2 \ kJ}}$

Explanation:

We are asked to find how many kilojoules of energy would be required to heat a block of aluminum.

We will use the following formula to calculate heat energy.

$q=mc \Delta T$

The mass (m) of the aluminum block is 225 grams and the specific heat (c) is 0.897 Joules per gram degree Celsius. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature.

ΔT = final temperature - inital temperature

The aluminum block was heated from 23.0 °C to 73.5 °C.

ΔT= 73.5 °C - 23.0 °C = 50.5 °C

Now we know all three variables and can substitute them into the formula.

m= 225 g
c= 0.897 J/g° C
ΔT= 50.5 °C

$q= (225 \ g )(0.897 \ J/g \textdegree C)(50.5 \textdegree C)$

Multiply the first two numbers. The units of grams cancel.

$q= (225 \ g * 0.897 \ J/g \textdegree C)(50.5 \textdegree C)$

$q= (225 * 0.897 \ J / \textdegree C)(50.5 \textdegree C)$

$q= (201.825\ J / \textdegree C)(50.5 \textdegree C)$

Multiply again. This time, the units of degrees Celsius cancel.

$q= 201.825 \ J * 50.5$

$q= 10192.1625 \ J$

The answer asks for the energy in kilojoules, so we must convert our answer. Remember that 1 kilojoule contains 1000 joules.

$\frac { 1 \ kJ}{ 1000 \ J}$

Multiply by the answer we found in Joules.

$10192.1625 \ J * \frac{ 1 \ kJ}{ 1000 \ J}$

$10192.1625 * \frac{ 1 \ kJ}{ 1000 }$

$\frac {10192. 1625}{1000} \ kJ$

$10.1921625 \ kJ$

The original values of mass, temperature, and specific heat all have 3 significant figures, so our answer must have the same. For the number we found, that is the tneths place. The 9 in the hundredth place tells us to round the 1 up to a 2.

$10.2 \ kJ$

Approximately 10.2 kilojoules of energy would be required.

3 0

2 years ago