Is the work done to overcome gravity by an object with a weight of 1n, which is accelerated vertically or raised 1m vertically at a uniform speed, 1J? Is work done by overcoming gravity the work done by gravity?
Work against gravity is the same
however
The work done on objects is different
Because uniform velocity means that the resultant force is zero
The pull exerted on an object is equal to gravity
Acceleration must be greater than gravity to produce acceleration
It is easy to infer that the work done by the latter is greater than the former
RELATED INFORMATIONS
- 1. When a 1n heavy object is lifted 1m high, the work done by the force on the object must be equal to 1J This sentence is wrong. Why?
- 2. I found this, ∵ 1pA * 1m & # 179; = 1n / m2 * 1m & # 179; = 1n · M = 1J work = pressure * volume
- 3. After the player kicks the football out, the work done by the football in the air is (air resistance is not included) a. How does kick work on the ball b. Gravity does work on the ball c. There is no force to work on the ball d. Not sure
- 4. When the ball with a mass of 1kg is released freely from 3m, the resistance of the ball is 0.1 times of the gravity The ball with a mass of 1kg is released freely from 3m. The resistance of the ball in motion is 0.1 times that of gravity. Assuming that the ball does not lose mechanical energy when colliding with the ground, the path of the ball from the beginning to the final rest is determined
- 5. On a smooth horizontal plane, there is a uniform thin plate with a mass of 4kg, which moves at a uniform speed of 3m / s. A 1kg ball falls into point a 20 m above the plate and rebounds to 5M high. The collision lasts for a very short time, and the gravitational impulse can be ignored 1. The elastic impulse of the plate to the ball during the collision 2. The dynamic friction coefficient between the plate and the ball is 0.08, and the velocity and direction of the plate after collision are calculated Does the ball have a horizontal speed after touch? If so, send it out 3. When the ball falls back on the board again, the distance between the ball's landing point on the board and a
- 6. There is a steel plate placed horizontally on the ground. There is a steel ball with mass m = 1kg at 3M above it. It moves vertically downward at the initial velocity V0 = 2m / s. assuming that the ball is subject to a constant air resistance f = 2n, there is no kinetic energy loss when the ball collides with the steel plate, and the ball finally stops moving (1) What's the speed of the first bounce? (2) The height of the first bounce? (3) What's the distance s it takes to stop?
- 7. At a height of 45m from the ground, a small ball with a mass of 0.1kg starts to fall freely. The instantaneous power of gravity at the end of the first second? The average power of gravity work in the second second second?
- 8. The ball with mass of M = 1kg rolls down from point a at the upper end of 1 / 4 smooth circular arc groove with radius r of 1, and leaves the circular arc horizontally at point B at the height h = 3M above the ground (1) The velocity VA when leaving the circular groove (2) Landing speed VC size (3) The work done by gravity throughout the process
- 9. A basketball with a gravity of 5N is thrown vertically. It is assumed that the resistance of air to the basketball is 0.5N, Then the resultant forces of the basketball in the process of vertical rising and falling are (10N / kg) A.5.5N,5N B.5.5N,4.5N C.4.5N,5.5N D.5N,4.5N
- 10. If the ratio of the initial velocity to the velocity back to the throwing point is k, and the air resistance is constant during the motion, the ratio of gravity to resistance is K______ .
- 11. The object with weight of 1n is increased by 1m under the action of vertical tensile force. Why is the work done by tensile force not 1J
- 12. Lift an object with a gravity of 1n by 1m, do work by 1J, do work by gravity by 1J, and the gravitational field sucks the object past If you lift an object with a gravity of 1n by 1m and do work of 1J, the gravitational field will absorb the object. However, if you want to separate the object, you also need to do work. What is the total energy of the universe Is it conservation? I don't know whether to fill in a specific number, anyway, the topic is like this
- 13. Does gravity work on a football when it's flying in the air? Be accurate!
- 14. There is an apple of 2n weight. By gravity and air resistance, we can calculate the resultant force F1 and F2 when it rises and falls in the process of throwing upward Why F1 = G + F resistance? F2 = G-F resistance?
- 15. An apple with a mass of 0.2kg is thrown up vertically, and the air resistance in the process of rising and falling is 1n
- 16. Draw a graph of the gravity of the object below. G = 10 N / kg (1) a small ball with a mass of 8 kg when it falls freely in the air (excluding air resistance)
- 17. When an apple is thrown up, it is subjected to gravity and air resistance The resultant force of apple in the process of rising -- the resultant force of apple in the process of falling
- 18. As shown in the figure, the mass ratio of a and B is Ma: MB = 3:2. They were originally stationary on the flat car C. There is a compressed spring between a and B. the dynamic friction coefficient between a and B and the upper surface of the flat car is the same, and the ground is smooth. When the spring is suddenly released, there is () A. A, B, C system momentum conservation B. A, B system momentum conservation C. car remains stationary D. car moves to the right
- 19. In the "urban and rural cleaning project", an environmental sanitation team rents a number of vehicles with a carrying capacity of 8 tons to transport a batch of construction waste. If each vehicle only contains 4 tons, then 20 tons of construction waste is left; if each vehicle is full of 8 tons, then the last vehicle is not empty. How many vehicles does the environmental sanitation team rent?
- 20. The displacement time relation of a car motion is x = 8t-2t & # 178;, then the following statement is correct (multiple choice) A. The car decelerates evenly B. The initial speed of the car is 8 m / s C. The acceleration of the car is - 2m / s and 178; D. The car stopped in two seconds