All categories

3 years ago

Tommy was walking at a rate of 4

1 answer:

8 0

A positive acceleration indicates that the object sped up. This means that if you compare the first speed to the second, the second speed should be higher.

A negative acceleration indicates that the object has slowed down. This means that if you compare the first speed to the second, the second speed should be lower.

If an acceleration is 0, it means that it neither slowed down nor sped up.

Now let us analyze your problem by listing down the speed and the time:

At noon: 4 mi/hr
12:30 : 6 mi/hr
2:30 : 2 mi/hr

From noon to 12:30, you will notice that there is an increase in speed. This means that Tommy had a positive acceleration. (Rules out D.)

From 12:30 to 2:30, there is a decrease in speed. This would indicate that Tommy had a negative acceleration. (Rules out C.)

No speed was the same, so acceleration was never 0. (Rules out A.)

From the assumptions above, we can now deduce that the answer is B.

You might be interested in

In equation δhsoln=δh1+δh2+δh3 which of the energy terms for dissolving an ionic solid would correspond to the lattice energy?

LekaFEV [45]

The dissolution of a solute in a solvent to form a solution usually occur in three steps, which are delta H1, delta H2 and delta H3.
For dissolving an ionic solid, the lattice energy, which is the energy that is holding the ionic particles in place correspond to DELTA H2 and it is the energy that must be conquered. The higher the charge in the ionic solid, the higher the lattice energy. The lattice energy must be overcome in order for the solid to dissolve.

4 0

3 years ago

A 60.0 g block of iron that has an initial temperature of 250. °C and 60.0 g bloc of gold that has an initial temperature of 45.

Maslowich

Answer:

The final temperature at the equilibrium is 204.6 °C

Explanation:

Step 1: Data given

Mass of iron = 60.0 grams

Initial temperature = 250 °C

Mass of gold = 60.0 grams

Initial temperature of gold = 45.0 °C

The specific heat capacity of iron = 0.449 J/g•°C

The specific heat capacity of gold = 0.128 J/g•°C.

Step 2: Calculate the final temperature at the equilibrium

Heat lost = Heat gained

Qlost = -Qgained

Qiron = -Qgold

Q=m*c*ΔT

m(iron) * c(iron) *ΔT(iron) = -m(gold) * c(gold) *ΔT(gold)

⇒with m(iron) = the mass of iron = 60.0 grams

⇒with c(iron) = the specific heat of iron = 0.449 J/g°C

⇒with ΔT(iron)= the change of temperature of iron = T2 - T1 = T2 - 250.0°C

⇒with m(gold) = the mass of gold= 60.0 grams

⇒with c(gold) = the specific heat of gold = 0.128 J/g°C

⇒with ΔT(gold) = the change of temperature of gold = T2 - 45.0 °C

60.0 *0.449 * (T2 - 250.0) = -60.0 * 0.128 * (T2 - 45.0 )

26.94 * (T2 - 250.0) = -7.68 * (T2 - 45.0)

26.94T2 - 6735 = -7.68T2 + 345.6

34.62T2 = 7080.6

T2 = 204.5 °C

The final temperature at the equilibrium is 204.6 °C

5 0

3 years ago

Formula for Zinc Bromide

charle [14.2K]

ZnBr2. hopes this helps

6 0

3 years ago

Read 2 more answers

HELP Which of the following fractions can be used in the conversion of 32 m3 to the unit mm3?

poizon [28]

We know that each millimeter contains 10⁻³ meters. Writing this as a ratio:
1 mm : 10⁻³ m

We require a conversion from m³ to mm³, so we must take the cube of the ratio we have made:
1 mm³ = (10⁻³)³ m³

Therefore, the conversion used will be:
(1 mm / 10⁻³ m)³

When we multiply by this conversion, we will get:
32 m³ = 32 x 10⁹ mm³

7 0

3 years ago

In 1990, the northern spotted owl was listed as endangered. Because of this, millions of acres of forests in the Pacific

Gwar [14]

Answer:

the endangered spices act

Explanation: The US Endangered Species Act (ESA) is our nation's most effective law to protect at-risk species from extinction, with a stellar success rate: 99% of species listed on it have avoided extinction.

8 0

3 years ago