Final test on the topic of strength. Test “Forces in nature. The force of friction arises

Correct answers are marked with +

1. Acceleration - is there?

A. first derivative of speed with respect to time +

B. second derivative of speed with respect to time

B. first derivative of the radius vector with respect to time

D. second derivative of the radius vector with respect to time +

2. Types of forces in mechanical movement?

A. elastic force +

B. force of attraction +

B. Gravity +

G. friction force +

3.What is deformation?

A. body shape change +

B. change in body size

B. change in the appearance of the body

D. change in body speed

4. Name the types of deformation

A. compression +

B. fracture

B. torsion +

G. bend +

5. Cause of deformation?

A. thermal expansion

B. action external forces

B. the action of internal forces

D. movement of body particles relative to each other +

6. Consequence of deformation?

A. the emergence of gravity

B. the emergence of an elastic force +

B. the occurrence of friction force

G. the occurrence of mechanical force

7.Dry friction divided by?

A. sliding friction +

B. contact friction

B. rolling friction +

G. rotational friction

8. How is the deformation coefficient determined?

A. Spring length

B. thick spring

B. spring rate +

G. spring compression

9.Formula expression of mechanical work

test 10. mechanical power- This?

A. Incandescent light bulb

B. the ratio of work to the time for which it is completed +

B. the ratio of time to work

D. there are no correct answers

11. What is called energy?

A. single measure different forms motion of matter

B. physical quantity, showing the work of the body

B. both are true +

G. both are wrong

12. Mechanical energy due to the movement of the body - is it?

A. kinetic energy

B. potential energy

B. internal energy

G. electrical energy

13. Is work equal to zero?

A. never

B. only if the force or displacement is zero

B. only if the force is perpendicular to the displacement

G. both the second and third options are correct +

14. What are rotational movements?

A. curvilinear movements

B. movement of body points in a circle

B. both are true +

G. both are wrong

Test update 2018

Correct answers are marked with +

1. Uneven movement It happens:

a) uniformly accelerated;

b) equally slow;

c) uniformly accelerated and uniformly slowed down; +

2. When uniformly accelerated motion point acceleration is called:

a) value equal to the ratio change in speed, change in the time for which this change occurred;

b) a value equal to the ratio of the change in speed, the change in time for which this change did not occur; +

3. What is the name of the system on which external forces or the sum of all external forces does not act is called:

A) insulating;

B) closed;

C) insulating (closed); +

4. For insulating system impulse:

A) does not change +

B) changes;

C) both options are wrong;

5. When considering mechanical movement have to deal with the following types of forces:

A) The force of friction, the force of gravity, the force of elasticity; +

B) friction force and elastic force;

C) only the force of elasticity;

6 test. The elastic force occurs when:

A) stretching the spring

B) Spring compression;

C) when stretching and compressing the spring; +

7. The strength of elasticity is:

A) The force in which the state of the body is restored, which was before the compression and tension of the spring or other body; +

B) The force at which the state of the body that was before the compression and tension of the spring or other body is not restored;

C) The force at which the state of the body is restored, which was not there before the compression and tension of the spring or other body;

8. Deformation of the body is called:

A) Change in body shape or size; +

B) Changing only the form;

C) Change only the size;

9. Types of deformation:

A) compression, torsion, bending; +

B) Compression and bending;

B) bending and twisting;

10. Hooke's law is:

A) the elastic force arising from the proportional elongation of the body and is directed to the opposite movement of the body during deformation; +

B) the elastic force that does not occur when the body is proportionally elongated and is directed to the opposite movement of the body during deformation;

C) both options are correct;

11. The reason for the deformation is:

A) the movement of body parts, a consequence of the deformation phenomenon of the emergence of elastic forces; +

B) the movement of body parts, a consequence of the deformation phenomenon of the emergence of gravity;

C) the movement of body parts, a consequence of the deformation phenomenon of the emergence of a friction force;

12. Friction force arises:

A) in direct contact of the bodies and is always directed along the contact surface; +

B) in direct contact of bodies, it is not always directed along the contact surface;

C) both options are correct;

13. Dry friction forces are divided into:

A) rolling friction;

B) sliding friction;

C) sliding and rolling friction; +

14. Law gravity bodies are:

A) any falling bodies move with acceleration vertically downwards, unless an opposite force acts on them; +

B) any falling bodies move with acceleration vertically downwards if an opposite force acts on them;

C) individual falling bodies move with acceleration vertically downwards, unless an opposite force acts on them;

15. The force acting on the body is:

A) the gravitational force of the earth +

B) the force of gravity of the sky;

C) both of the proposed options are correct;

test - 16. The law of gravity of the body is:

A) the force with which bodies are attracted to each other is proportional to the mass of the body and inversely proportional to the distance between them; +

B) the force with which bodies are attracted to each other in proportion to the mass of the body and only;

C) there are no correct options;

17. One of the manifestations of the forces of universal gravitation is:

A) these are the forces of attraction of bodies to the Earth, which is called gravity; +

B) these are the forces of attraction of bodies to the Earth, which is called the force of elasticity;

C) these are the forces of attraction of bodies to the Earth, which is called the sliding force;

18. The measure of energy transfer is:

A) a physical quantity called work;

B) a physical quantity called power; +

C) a physical quantity called energy;

19. There are several types of mechanical energy, namely:

A) kinetic;

B) potential;

C) kinetic and potential; +

D) there is no correct answer;

20. Complete mechanical energy is equal to:

A) the amount of kinetic energy;

B) the amount of potential energy;

C) the sum of kinetic and potential energy; +

21. Total mechanical energy is always:

A) permanent +

B) not constant;

C) there is no correct answer;

22. A force acts on each material point:

A) both from the side of points and from the side of force; +

B) does not work at all;

C) there is no correct answer;

23. Momentum of material points:

A) is equal to the sum impulses of these material points; +

B) is not equal to the sum of the impulses of these material points;

C) there is no correct answer;

24. The line along which the movement occurs is called:

A) troictoria of movement; +

B) has no name;

C) there is no correct answer.

Option 1.

1. What force changes the direction of motion of a stone thrown horizontally?
a) elastic forces; b) gravity; c) body weight.

2. What is approximately equal to the force of gravity acting on a ball with a mass of 0.5 kg?
a) 5 N; b) 0.5 N; c) 50 N.

3. What is the approximate mass of a body weighing 120 N?

a) 120 kg; b) 12 kg; c) 60 kg.

4. The force resulting from the deformation of the body and directed in the direction opposite to the movement of the particles of the body is called ...

a) elastic force; b) friction force; c) gravity.

5. A man weighing 80 kg is holding a bag weighing 10 kg on his shoulders. With what force does a person press on the ground?

a) 800 N; b) 700 N; c) 900 N.

6. The thrust force of a rocket launched vertically upwards is 400 kN, and the gravity force acting on the rocket is 100 kN. Determine the resultant of these forces.

a) 400 kN; b) 500 kN; c) 300 kN.

7. In the icy sidewalks are sprinkled with sand, while the friction force of the soles on the ice ...

a) is decreasing b) increases; c) does not change.

8. A skydiver weighing 85 kg uniformly descends with an open parachute. What is the force of air resistance if the parachutist moved uniformly?

a) 85 N; b) 850 N; c) 8.5 N.

9. There is water in the tank of the street sprinkler. By how much will the weight of the car decrease if it spills 200 kg of water?

a) 200 N; b) by 2 kN; c) 20 kN. 1 2 3

10. (creative) Give examples where friction can be harmful. What are some ways to reduce friction?

Test in physics in grade 7 on the topic "Forces"

Option 2

1. What force causes the formation of rockfalls in the mountains?

a) elastic forces; b) gravity; c) friction force.

2.. What is approximately equal to the force of gravity acting on a brick with a mass of 3 kg?
a) 3 N; b) 0.3 N; c) 30 N.

3. What is the approximate mass of a chandelier suspended from the ceiling, acting on the ceiling with a force of 50 N?

a) 50 kg; b) 4 kg; c) 5 kg.

4. The force with which the body, due to attraction to the Earth, acts on a support or suspension

a) elastic force; b) gravity; c) body weight.

5. A boy weighing 400 N holds a weight of 10 kg on his outstretched arm. Determine the force with which he presses on the ground.

a) 500 N; b) 400N; c) 300 N.

6. An electric locomotive pulls cars with a force of 300 kN. The resistance force is 170 kN. Calculate the resultant of these forces.

a) 470 kN; b) 130 kN; c) 300 kN.

7. When lubricating rubbing surfaces, the friction force ...

a) does not change; b) increases; c) decreases.

8. A weight of 400 g was suspended from a spring. What is the elastic force that arose in it?

a) 4 N; b) 0.4 N; c) is equal to zero.

9. There is a load in the car. By how much will the weight decrease if 500 kg of cargo is unloaded?

a) 500 N; b) by 5 kN; c) 50 kN.

10. (creative) Give examples where friction can be helpful. What are some ways to increase friction?

Force physics test Grade 7 with answers. The test includes 3 options. Each option has 6 tasks.

Option 1

1. During the interaction of two bodies they have ... .

1) both shape and speed can change
2) neither speed nor shape changes
3) only the shape changes
4) only speeds change

2. The result of the action of force depends on ... .

1) only from the module of this force
2) only on the direction of this force
3) only from the point of application of this force
4) and from the module, and from the direction, and from the point of application of force

3. The modulus of elasticity of the stretched rope (k is the rigidity of the rope) shown in the right figure is ... .

1) cl
2) kl 0
3) k(l − l 0)
4) k(l + l0)

4. Gravity is the force with which...

1) The earth pulls the body towards itself
2) the body pulls the earth towards itself
3) the body is attracted to the mass standard
4) the body presses on the scales

5. The value of the sliding friction force depends on ... .

1) only from the material of contacting bodies
2) only on the degree of their processing (roughness)
3) only from the force pressing one body to the surface of another
4) from all the above factors

6. The force acting from the side of the finger on the orange, and the resultant force applied to this orange, respectively, are equal to ....

1) 4 N and 1 N
2) 1 N and 0 N
3) 4 N and 0 N
4) 1 N and 4 N

Option 2

1. A body affected by another body may change ... .

1) only numerical value speed
2) speed direction only
3) form only
4) and the numerical value of the speed, and its direction, and form

2. The change in the velocity vector of a body under the action of a force on it ... .

1) depends only on the modulo of this force
2) depends only on the direction of this force
3) depends on both the modulus of force and its direction
4) does not depend on the modulus of force, nor on its direction

3. The modulus of the elastic force of the compressed spring (k is the stiffness of the spring) shown in the right figure is ... .

1) cl
2) kl 0
3) k(l − l 0)
4) k(l + l0)

4. The value of the force of gravity acting on the body depends on ... .

only on body weight
only on the height at which the body is located
only from the geographical latitude of the point where the body is located
all of the above factors

5. The friction force is measured when a metal bar moves along a plate of the same material, gradually polishing both contacting surfaces. As the bar and plate become smoother and smoother, the frictional force will be ... .

1) constantly decrease
2) constantly increase
3) stay the same
4) first decrease, then increase

6. The force acting on the eggplant from the side of the finger, and the resultant force applied to this eggplant, respectively, are equal to ....

5 N and 0 N
5 N and 2 N
3 N and 0 N
3 N and 5 N

Option 3

1. The body, acting on another body, ... .

1) can change its speed but cannot change its shape
2) can change both its speed and its shape
3) can change its shape, but cannot change its speed
4) can neither change its speed nor its shape

2. First, the force was applied to the center of the rod lying on the table. Then, the force of the same modulus and direction was applied to the end of the rod, while the nature of the motion of the rod ... .

1) will not change, since in both cases the forces are equal in absolute value
2) will not change, since in both cases the forces are in the same direction
3) will change, since the point of application of force in these two cases is different
4) may remain the same, or may change, since the force can be directed both along the rod and at an angle to it

3. If l 0 is the length of the unstretched spring, and l is the length of the stretched one, k is the stiffness of the spring, then the elastic modulus of the stretched spring is ... .

1) cl
2) kl 0
3) k(l − l 0)
4) k(l + l0)

4. On what bodies (a house, the Moon, a leaf falling from a tree) does gravity act constantly?

only for home
only to the moon
only on a leaf falling from a tree
all of the above bodies

5. The cause of the friction force between two bodies is … .

1) is associated only with the mutual repulsion of molecules located on the surface of bodies
2) is associated only with the mutual attraction of molecules located at the points of contact of the bodies
3) is associated with both attraction and repulsion of molecules located at the points of contact of bodies
4) is not associated with the interaction of molecules of contacting bodies

6. The distance between the nearest divisions of the spring scales shown in the figure is 1 cm. The spring stiffness of the dynamometer is approximately equal to ....

1) 1000 N/m
2) 500 N/m
3) 140 N/m
4) 10 N/m

Answers to the test in physics Force Grade 7
Option 1
1-1
2-4
3-3
4-1
5-4
6-2
Option 2
1-4
2-3
3-3
4-4
5-4
6-3
Option 3
1-2
2-4
3-3
4-4
5-3
6-1