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1. Because the train moves in a straight line at a uniform speed, the force is balanced, and the resistance is equal to the traction force: F = 1000N
2. Train speed: v = s / T = (2000m-500m) ÷ 30s = 50M / S
Note: the time of the whole train on the bridge refers to the time it takes for the tail of the train to be at the end of the bridge and there is still a car length at the tail of the train from the other end of the bridge
Which point to explain, please point out and ask
What is the resistance of the vehicle with a mass of 2000kg when it starts from the station under the traction of 2400N and reaches 72km \ h after 20s?
72km / h = 20m / s, so a = 1m / S ^ 2, f resultant force = 2000N, so f = 400N
Please give examples: (1) force can change objects; (2) Force can change the motion state of an object; (3) The action effect of force is related to the magnitude and direction of force It depends on the point of action
(1) Squeeze the plasticine hard and the shape of the plasticine changes
(2) Kick football hard. Football starts from rest
(3) The greater the force, the more variable the shape of the spring
The direction of the force pushes the wood block to move on the horizontal plane, force to the left, the wood block moves to the left, force to the right, and the wood block moves to the right
The action point of force is at different action points, and the difficulty of opening the door is different
A fully loaded vehicle with a total mass of 4000kg starts from a standstill and runs along the road. The vehicle traction is 6000N and the resistance is 4000N. Find the vehicle Find the acceleration of the car and the speed at the end of 20 seconds (G is 10m / S ^ 2)
Acceleration: a = f / M = (6000-4000) / 4000 = 0.5m/s2
The speed after 20s is: v = at = 0.5x20 = 10m / s
You should be right. You can't forget it when you're old
The vehicle with a mass of 2T moves in a straight line along the horizontal highway. The traction force on the vehicle is 2000N and the resistance is 0.01 times the vehicle weight. Calculate the resultant force on the vehicle. (G is taken as 10N / kg)
G=mg=2000kg × 10N/kg=2 × 104N
f=0.01G=0.01 × two × 104N=200N
F = f-f = 2000n-200n = 1800n, the direction is the same as the traction direction
A: the resultant force on the vehicle is 1800n, and the direction is the same as the traction direction
A truck with a mass of 4000 kg drives along the highway from a standstill. It is known that the traction force of the vehicle in the horizontal direction is always 6000N A truck with a mass of 4000 kg starts from a standstill and travels along the road. It is known that the traction force of the car in the horizontal direction is always 6000N and the resistance is 2000N. Calculate the resultant force on the car, the acceleration of the car, and the distance traveled within the first 5S when the car starts to move
The resultant force is equal to 6000-2000 = 4000N
Acceleration = 4000 / 4000 = 1m / s Square
The end speed of 5S is equal to 0 + 1 * 5 = 5 m / s, and the average speed is equal to (0 + 5) / 2 = 2.5 m / s
Distance = 2.5 × 5 = 12.5m
RELATED INFORMATIONS
- 1. When a vehicle with a rated power of 40kW runs on a horizontal highway, the resistance is always 2000N and the vehicle mass is 1000kg, If the vehicle starts to move in a straight line with uniform acceleration from standstill, the acceleration is 2m / S ^ 2, and the resistance in motion is constant. Find: (1) the maximum speed that the vehicle can reach; (2) The time for the car to accelerate evenly; (3) Work done by the engine in the first 20s
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