Ask for a set of physics papers, and ask for a physics test paper answer

Hehe, what do you have to do after the exam.

Absolutely! The 5th of ", Little One", I have done it, it seems to be c, and the 2nd of "-100 million touches the night" must be wrong.

Go to my blog and find a lot about physics! **：

Solution: (1) the trolley on the horizontal desktop is subjected to the force f1 of the horizontal to the left and the force f2 of the horizontal to the right, f1 and f2 are equal to the gravity of the hook code at the left and right ends of the horizontal desktop, two hook codes are hung at both ends of the desktop, the heavy pure Zen force of the hook code is equal, F1 and F2 are equal, the direction is opposite, and act on the same straight line, these two forces are a pair of balanced forces, and the car will be in a stationary state;

So the answer is: stillness

2) the pulling force f1 and f2 of the trolley are equal to the gravity of the hook code at both ends of the horizontal desktop, and the size of f1 and f2 can be changed by adjusting the number of hook codes of the trousers;

So the answer is: the number of hooks

3) Twist the trolley at an angle by hand, the force f1 and f2 of the trolley are not in a straight line, and the trolley is no longer subject to a pair of balancing forces, and the trolley will rotate;

So the answer is: turn

1 Stillness. 2. Number of weights.

3. Twist back to the initial state and stand still.

Balance. Number of hooks.

Restore the original horizontal direction.

1.Reduce friction.

Because he is moving at a constant speed.

3.Kinetic.

4.Still replied to the high one.

5 g = mg, g = m is the mass of the object, that is, how much it weighs. Gravity is equal to 10kg* = 98 N.

6.How can I be this kind of problem again!! g = mg, g = m is the mass of the object = g g = 4900

7.First of all, the traction force asked in this question is equal to its frictional resistance, because it is a uniform motion ruler. So for a 4000kg imitation car, the gravity of 1 4 is 4000* = 9800 N.

8.This problem means that the speed of 96 time * 5 meters and seconds is greater than 500, so let's calculate 96 meters and seconds = 600 meters.

I declare that this man can get out alive

Finally, the child who wants to ask the question is not asking someone to answer the question for you.

1.Decrease by 2= 3.Luck this tease 4Stationary shelter 4 = 10000n l = 120 * 5 = 600m > macro hidden 500m so safe.

There is one hollow aluminum ball and one iron ball with the same volume and mass, of which the hollow part of the iron ball accounts for two-thirds of the total volume. It is known that the ratio of the volume of the aluminum ball to the hollow part of the iron ball is 1:9 If two hollow balls are melted to make a solid alloy ball, the density of the alloy ball is 4 g cm3 (keep the integer).

Click to enlarge to view, and ignore the answers on the diagram for multiple-choice questions.

Multiple Choice Answers:

1～5：ccbcd

6~10：ccdca

11～17：bcdbacc

Fill in the blanks before the first few pictures, from the answers after question 10:

10. Vibration and tone.

11. Transmit energy and information.

12. Up, refraction.

13. Convex and strong.

14. Focal length, upright magnified imaginary.

4. Solution: v=4590m s

2) The solid sound transmission effect is good, this is not very certain. <>

The first question is C. The trouble is a little bigger, and I can't see it clearly.