What is air A. A Buchner substance B. A compound C. An element D. A mixture

Which cell structure is found in plant cells but not in animal cells?

o-na [289]

Answer:

B). Cell wall

Explanation:

a cell wall gives the plant cell its rigid box like shape, which animal cells do not have since they do not have cell walls.

4 0

3 years ago

An object is dropped at a height of 6 m from the ground. How fast is it moving just before it hits the ground?

maw [93]

Explanation:

Given:

Δy = 6 m

v₀ = 0 m/s

a = 9.8 m/s²

Find: v

v² = v₀² + 2aΔy

v² = (0 m/s)² + 2 (9.8 m/s²) (6 m)

v ≈ 10.8 m/s

Round as needed.

3 0

3 years ago

Consider a 10 gram sample of a liquid with specific heat 2 J/gK. By the addition of 400 J, the liquid increases its temperature

stich3 [128]

40 J/g is the heat of vaporization of the liquid.

Answer: Option D

Explanation:

Given that mass of liquid sample: m = 10 g

And, Specific heat of the liquid: S = 2 J/g K

Also, the increase in the temperature of the liquid, $\Delta T = T_{2}-T_{1} = 10 K$

Therefore, the total amount of heat energy required is given by:

$q_{1} = m \times S \times\left(T_{2}-T_{1}\right) = 10 \times 2 \times 10 = 200 J$

According to the given data in the question,

Total heat energy supplied, q = 400 J

Rest of heat would be $q_{2}=q-q_{1}=400-200=200 \mathrm{J}$

Now, 200 J vaporizes the mass, half of the liquid from full portion boiled away. So,

$m^{\prime} = \frac{10}{2} = 5 \mathrm{g}$

Latent heat of vaporization of the liquid is $L_{v}$ . It can be calculated as below,

$q_{2} = m^{\prime} L_{v}$

$L_{v} = \frac{q_{2}}{m^{\prime}} = \frac{200}{5} = 40 \mathrm{J} / \mathrm{g}$

5 0

3 years ago

A 39-cm-long vertical spring has one end fixed on the floor. Placing a 2.2 kg physics textbook on the spring compresses it to a

tensa zangetsu [6.8K]

To solve this problem we will apply Hooke's law. Which says that the force on a spring is equivalent to the product between the elastic constant and the displacement of the spring.

$F = k x$

Here,

k = Spring constant

x = Displacement

Rearranging to find the spring constant,

$k = \frac{F}{x}$

Spring compresses it to 29 cm so

$x = 39- 29 = 10 cm$

$k = \frac{mg}{x} \rightarrow$ The force in this case is equivalent to the weight of the spring

$k = \frac{2.2 * 9.8}{10 * 10 ^ {-2}}$

$k = 215.6N/m$

Therefore the spring constant is 215.6N/m

3 0

3 years ago

A car accelerates uniformly from 0 km/hr to 60 km/hr in 4.5 seconds. Which one of the following choices best represents the acce

gizmo_the_mogwai [7]

Answer:

The acceleration of the car is $3.7\ m/s^2$ .

Explanation:

It is given that,

Initial speed of the car, u = 0

Final speed of the car, v = 60 km/h = 16.66 m/s

Time, t = 4.5 s

We need to find the acceleration of the car. It is equal to the change in velocity divided by time taken. It can be given by :

$a=\dfrac{v-u}{t}\\\\a=\dfrac{16.66-0}{4.5}\\\\a=3.7\ m/s^2$

So, the acceleration of the car is $3.7\ m/s^2$ . Hence, this is the required solution.

4 0

3 years ago

What is air￼ A. A Buchner substance B. A compound C. An element D. A mixture

What is air A. A Buchner substance B. A compound C. An element D. A mixture