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SashulF [63]
3 years ago
8

In nature, hot air tends to rise and cool air tends to sink. This is behind the concept of convection heating that is used in ov

ens. Convection currents occur only in fluids such as liquids and gases but not in solids.
Which of the examples below is an example of convection?
A) rubbing your hands together.
B) heating a fish tank.
C) basking in the sun.
D) striking a match.
Physics
2 answers:
Nataly_w [17]3 years ago
7 0
Answer: Heating a fish tank
drek231 [11]3 years ago
6 0

Answer:

<h2>B</h2>

Explanation:

MODES OF HEAT TRANSFER

1) Conduction: This type of heat transfer happens when there is direct contact between the two object.

2) Convection: This type of heat transfer happens when there is a movement of fluid (liquid or gas).

3) Radiation: This type of heat transfer happens when there is direct transfer of energy through space.

A. Rubbing your hands together, is a type of energy transformation in which mechanical energy transforms to heat energy.

<h3>B. Heating a fish tank: Hot liquid tends to rise and cool liquid tends to sink and thus the fish tank heats.</h3>

C. Basking in the sun: is a type of radiation as the sun energy is transferred through space.

D. Striking a match: is a energy transformation in which mechanical energy transforms to heat and light energy.

please make me brainlist

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Which type of energy is released when a bond between atoms is broken
scoray [572]

Answer:

D

Explanation:

7 0
3 years ago
Two blocks are connected by a light weight, flexible cord that passes over a frictionless pulley.Ifm1=2 kg and m2 = 3 kg, and bl
Vera_Pavlovna [14]

Answer:

t = 1.41 sec.

Explanation:

If we assume that the acceleration of the blocks is constant, we can apply any of the kinematic equations to get the time since the block 2 was released till it reached the floor.

First, we need to find the value of  acceleration, which is the same for both blocks.

If we take as our system both blocks, and think about the pulley as redirecting the force simply (as tension in the strings behave like internal forces) , we can apply Newton's 2nd Law, as they were moving along the same axis, aiming at opposite directions, as follows:

F = m₂*g - m₁*g = (m₁+m₂)*a (we choose as positive the direction of the acceleration, will be the one defined by the larger mass, in this case m₂)

⇒ a = (\frac{(m₂-m₁)}({m₁+m₂} * g = g/5 m/s²

Once we got the value of a, we can use for instance this kinematic equation, and solve for t:

Δx = 1/2*a*t² ⇒ t² = (2* 1.96m *5)/g = 2 sec² ⇒ t = √2 = 1.41 sec.

6 0
3 years ago
A force of 25N acts on a mass of 5.0kg, initially at rest. Calculate the distance travelled before achieving a velocity of 20m/s
spin [16.1K]

Answer:

40m

Explanation:

let's calculate the acceleration first

force = mass × acceleration

rearranging to find acceleration:

acceleration = force ÷ mass

force = 25N, mass = 5.0kg

acceleration = 25 ÷ 5 = 5ms^-2

we can now use the formula v^2 = u^2 + 2as where v = final velocity, u = initial velocity, a = acceleration and s = distance

rearranging v^2 = u^2 + 2as the distance is

s = (v^2 - u^2) ÷ 2a

v = 20, u = 0, a = 5

s = (20^2 - 0^2) ÷ (2 × 5) = 40m

the distance is 40m

6 0
2 years ago
1. A uniform magnetic field is directed vertically upwards. In which direction in this field should an alpha particle be project
max2010maxim [7]

Answer:

1. Fleming's left hand rule

2. It must be projected towards the east

Explanation:

Fleming's left-hand rule states that; When a current-carrying conductor is placed in an external magnetic field, the conductor experiences a force perpendicular to both the field and to the direction of the current flow. This rule was first put forward by John Ambrose Fleming in the later part of the nineteenth century.

Hence if the thumb, fore finger and middle finger of the lefthand are held mutually at right angles to each other; the thumb shows the direction of motion, the fore finger shows the direction of the field while the middle finger shows the direction of the current.

Hence, if the alpha particle is projected eastwards(at right angles) to the uniform magnetic field, it will be deflected southwards in the magnetic field.

3 0
3 years ago
True Or False? The tendency for an object in motion to remain in motion is called orbital speed.
Harlamova29_29 [7]

The correct answer to the question is False i.e the tendency of an object in motion to remain in motion is not called the orbital speed.

EXPLANATION:

Before going to answer this question, first we have to understand Newton's first laws of motion.

As per Newton's first laws of motion, every body continues to be in state of rest or of uniform motion in a straight line unless and until it is compelled by some external unbalanced forces.

Hence, as long as no unbalanced force is acting on a moving object, it will be in motion. This tendency of a moving object to be in motion is called inertia of motion of the body.

Inertia of motion is the property of the body by virtue of which a moving body always tries to be in motion.

Hence, the tendency of an object in motion to remain in motion is not called as the orbital speed.

7 0
3 years ago
Read 2 more answers
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