Junior high school physics measurement questions, junior high school physics, what are the physical

Big Big Because m=pv (density * volume) a b uhd d will not reduce the volume, and the density is related to the type and state of the substance, it does not change. So choose C

3.On the small side. Rust is to increase the weight quality, for example, 5g weight rust, then its actual quality is, so the item plus the number of views 5g is balanced. So the measured value is less than the actual value.

4.First of all, I want to say: Density unit: xx kg m3 See no kg. So first put the density = m v = 2kg cubic .

Density is related to species and state, so a is not true.

Reason is the same as above, B is incorrect.

The volume of the gas is v and the mass is m compress it, v is smaller, m constant density = m v the denominator is smaller. The numerator does not change, and the value becomes larger. then the density becomes larger.

Density = m v Both are equal, and there is no reason for the density to be unequal. So D is also wrong.

Woo woo woo am I easy? Hehe, I hope it helps.

1: Big, big.

2: C3: Small, because the mass of rusted weights is larger than that of rustless, and the reading calculation is based on the rustless weight.

4: p(density)=mv=2 (1l=cubic meter)5:c does it yourself, there may be mistakes,)

1。Light; Weight 3The measurement results are heavier than they actually are. Because the weights are heavier than before.

Measure the length with a meter ruler.

Measure time with a stopwatch.

Use electricity meters to measure voltage and current.

Measure the temperature with a thermometer.

Measure quality with a balance.

Measure the diameter with vernier calipers, spiral micrometers, 1,1. Measure the length with a scale.

2。Measure time with a stop watch or clock.

3。Measure the voltage with a voltmeter.

4。Measure the current with an ammeter.

5。Measure the temperature with a thermometer.

6。Measure quality with a balance.

7。Measure the volume with a graduated cylinder.

8。Force measurement with spring dynamometer, 1, 1Length: scale (ruler, tape measure) (special measuring method of imaginary side: cotton thread, roller, scale indirect measurement).

2.Liquid or solid volume: graduated cylinders, measuring cups, regular solids can be used with a scale.

3.Mass: balances (laboratory), electronic scales, rod scales, scales (daily life), spring dynamometer indirect measurement.

5.Speed: speedometer (on a car), average speed: ruler (tape measure), clock (stopwatch).

6.Temperature: liquid thermometer (for laboratory use); Thermometer (to measure body temperature).1,1.Length: scale (ruler, tape measure) (special measurement method: cotton thread, roller, scale indirect measurement).

2.Liquid or solid volume: graduated cylinders, measuring cups, regular solids can be used with a scale.

3.Quality: balances (laboratory), electronic scales, rod scales, scales (daily life), indirect measurement with elastic fiber rubber reed dynamometer.

5.Speed: speedometer (on a car), average speed: ruler (tape measure), clock (stopwatch).

6.Temperature: liquid thermometer (for laboratory use); Body erection thermometer (body temperature measurement).0,

Pressure: f=g=mg=1200kg*10n, swim deficiencykg=

Stress area s=500cm *4=2000cm=

The pressure of the car at rest on the water surface p=f mass grinding s=

No need for an answer, boy, I promise that the high school entrance examination will not be so troublesome.

Landlord, tell me your email address, and I'll send it to you in a word document!

a Parachutes must be equipped to ensure a safe landing on the Moon (there is no atmosphere on the Moon, parachutes are slowed down by the resistance of the air, so parachutes are useless on the Moon).

b A perpendicular line can be installed on the rover to allow for observation of the degree of inclination. (The Moon also has a gravitational pull, so yes)

c A compass should be equipped to determine the direction (the compass is indicated by the Earth's magnetic field, and the Moon has no magnetic field, so it is useless).

d A spare petrol engine can be installed for the rover for emergency use (there is no air on the moon and therefore cannot be used).

The angle may be 30 or 60, and the direction of reflection is different.

There is a convergence effect.

No atmospheric vacuum, no combustion, no optional d, no magnetic field can not be selected c, the compass is the use of magnetic field, such as China's astronauts out of the warehouse in space itself is floating, fortunately, the moon still has one-sixth of the earth's gravity, such a weak gravity can but does not necessarily have to be equipped with a parachute, not optional a. Therefore, choose B

Question supplement: 30 degrees; Convergence.

b Tell me if you have any questions.

A: There is no air on the moon, and parachutes need air to be used.

c There is no magnetic field, and the compass is useless.

dThere is no oxygen, and gasoline cannot be ignited.

degree convergence.

Choose BA weak gravity that the acceleration is very slow, no parachute is used.

c There is no magnetic field, and the compass is useless.

d gasoline engine has no oxygen, it can't be used.

Correct Answer: BA has no atmosphere, i.e., no air resistance, and cannot decelerate.

b Weak gravity, but there is gravity.

c The direction of the Moon's magnetic field cannot be determined.

dNo atmosphere, i.e., no air.

Convergence.

d, there is no atmosphere on the moon, so parachutes cannot be used; There is no magnetic field on the moon, so the compass cannot be used; There is no gravity on the Moon, so the reperpendicular line is useless. I've done this question no less than five times...Dig hahaha....

degrees or 30 degrees of focus.

The first one above says that gathering, and then they all say gathering, and some people say that they gather, and they say that they gather, and if you say it, please have a bit of a physical flavor, and the most formal way of saying it is to focus.

1. The convex lens is convergence, and the concave lens is divergent.

1) Mercury contains impurities.

If the mercury contains impurities, the density of the mercury column will decrease and the mercury column will rise. 2) The measurement method is wrong.

Note when measuring: It is to measure the vertical distance between the highest liquid level of the mercury column and the liquid level of the water tank, not to measure the distance of the mercury column in the glass tube).

Measuring along the mercury tube is the length of the mercury column, 760mm is the vertical height, if the pipe is tilted, the value will be greater than 760mm. So it will measure 770mm

1.Mercury is impure.

2.The local atmospheric pressure is higher than the standard atmospheric pressure.

3.The tube is tilted.

It is possible that a small amount of air may enter the interior, causing a small change in the difference between the internal air pressure and the external air pressure. The teacher should have talked about it in class.

Baseballs are unevenly shaped objects, and to measure their diameter, they need to use the auxiliary translation method, that is, the measured length is "translated" onto the scale.

The auxiliary equipment required is a horizontal tabletop, two triangle plates (or rectangular blocks), and a scale.

As shown below: Turn left|Turn right.