What is the total resistance in this circuit?

How much of Earth's surface is dry, ice-free land? *

AleksandrR [38]

Answer:

Less than a quarter of Earth's surfaces are dry, ice free lands

8 0

2 years ago

A person measures his or her heart rate by counting the number of beats in 30s. If 40±1 beats are counted in 30.0±0.5s, what is

nordsb [41]

Answer:

$Rate = 1.33 \pm 0.055$ beats per second

Explanation:

Number of heart beats = $40 \pm 1$

time taken = $30.0 \pm 0.5 s$

now we have

$N = 40 \pm 2.5$ %

$t = 30.0 \pm 1.67$ %

now rate of heart beat is defined as number of heart beat per unit of time

so we have

$Rate = \frac{N}{t}$

$Rate = \frac{40 \pm 2.5}{30 \pm 1.67}$

so we have

$Rate = 1.33 \pm (2.5 + 1.67 )$

$Rate = 1.33 \pm 4.17$ %

$Rate = 1.33 \pm 0.055$ beats per second

7 0

3 years ago

If the net force on a block is zero

amm1812

If the net force on a block is zero, the block will move at constant velocity

Explanation:

We can answer this question by applying Newton's second law of motion, which states that the net force on an object is equal to the product between its mass and its acceleration:

$\sum F = ma$ (1)

where

$\sum F$ is the net force on the object

m is its mass

a is its acceleration

In this problem, we have a block, and the net force on it is zero:

$\sum F = 0$

According to eq.(1), this also implies that

$a=0$

So, the acceleration of the block is zero.

However, acceleration is the rate of change of velocity of a body:

$a=\frac{\Delta v}{\Delta t}$

where $\Delta v$ is the change in velocity in a time of $\Delta t$ . Since the acceleration is zero, this means that $\Delta v=0$ , and therefore the velocity of the object is constant.

Learn more about Newton's second law:

brainly.com/question/3820012

#LearnwithBrainly

8 0

3 years ago

What is the difference between charging by contact and charging by induction in terms of electron transfer.

Veronika [31]

Answer:

the main difference between charging by contact and charging by induction is that in the first case, the two objects are touching, while in the second case, the two objects do not touch

Explanation:

There are three methods of charging an object:

- Charging by friction: this is done by rubbing an object against another object. An example is when a plastic rod is rubbed with a wool cloth. When this is done, electrons are transferred from the wool to the rod, so both objects remain charged at the end of the process

- Charging by contact: this is done by putting in contact a charged object with a neutral, conducting object. In this case, the charges are transferred from the charged object to the neutral object; at the end of the process, the neutral object will also have a net electric charge, so it will be also charged.

- Charging by induction: in this case, we take a charged object, and a neutral object, and we place the two objects close to each other, but without touching. Let's assume that the charged object is negatively charged: in this case, the positive charges in the neutral object are attracted towards the negative charges of the charged object, while the negative charges of the neutral object are repelled away. As a result, the positive and negative charges in the neutral object split apart. If the object is connected to the ground, then negative charges move away, so the neutral object will remain positively charged.

Therefore, the main difference between charging by contact and charging by induction is that in the first case, the two objects are touching, while in the second case, the two objects do not touch.

5 0

3 years ago

Mass refers to the gravitational force on the matter in contact with the surface of a planet

Arte-miy333 [17]

Answer: Yes and no.

Explanation: Mass is the amount of matter in an object, whereas weight is the force exerted on an object by gravity. Objects on the surface of the earth have weight, although sometimes the weight is difficult to measure.

8 0

3 years ago