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A train moves in a straight line at an initial speed of two meters per second and an acceleration of 0.5 meters per second. Find (1) what is the speed of the train at the end of three seconds? (2)... A train moves in a straight line at an initial speed of two meters per second and an acceleration of 0.5 meters per second. Find (1) what is the speed of the train at the end of three seconds? (2) What is the average speed in the first four seconds?
v0=2m/s
a=0.5m/s^2
Train speed at the end of three seconds V3 = V0 + at = 2 + 0.5 * 3 = 3.5m/s
Train speed at the end of four seconds V4 = V0 + at = 2 + 0.5 * 4 = 4m / S
Average speed in the first four seconds = (V0 + V4) / 2 = (2 + 4) / 2 = 3m / S
A train finished crossing two iron bridges at a speed of 600 meters per minute. Crossing the second iron bridge is 5 seconds longer than the one. It is also known that the length of the two iron bridges is 50 meters shorter than twice the length of the first iron bridge. Try to find the length of each iron bridge?
Train speed = 600 m / min = 10 m / S
Bridge 2 - bridge 1 = 5 * 10 = 50m
Bridge 1 = bridge 2-50
Bridge 2 + 50 = 2 bridge 1 = 2 (bridge 2-50)
Bridge 2 = 150
Bridge 1 = 100
A train had to cross the first and second iron bridges at a speed of 600 meters per minute. It took 5 seconds more to cross the second iron bridge than the first iron bridge. It is also known that the length of the second iron bridge is 50 meters shorter than twice the length of the first iron bridge. Try to find the length of each iron bridge
If the length of the first railway bridge is x meters, then the length of the second railway bridge is (2x-50) meters, and the time required to cross the first railway bridge is x600 minutes. The time required to cross the second railway bridge is 2x − 50600 minutes. According to the meaning of the question, the equation x600 + 560 = 2x − 50600 can be listed, and the equation x + 50 = 2x-50 can be solved to obtain x = 100, ‡ 2x-50 = 2 × 100...
A train had to cross the first and second iron bridges at a speed of 600 meters per minute. It took 5 seconds more to cross the second iron bridge than the first iron bridge. It is also known that the length of the second iron bridge is 50 meters shorter than twice the length of the first iron bridge. Try to find the length of each iron bridge
If the length of the first railway bridge is x meters, then the length of the second railway bridge is (2x-50) meters, and the time required to cross the first railway bridge is x600 minutes. The time required to cross the second railway bridge is 2x − 50600 minutes. According to the meaning of the question, the equation x600 + 560 = 2x − 50600 can be listed, and the equation x + 50 = 2x-50 can be solved to obtain x = 100, ‡ 2x-50 = 2 × 100...
For a vehicle traveling along a flat and straight road, the speed is 36km / h, and the acceleration obtained after braking is 4m / S ^ 2. Calculate the displacement of the vehicle in the last 2 seconds Please solve it as soon as possible What the hell is it, huh
S = 1 / 2att = 1 / 2 * 4 * 2 * 2 = 8M
The speed of a car traveling along a flat and straight road is 36km / h, and the acceleration obtained after braking is 4m / S2 Find ① the distance from the start of braking to the stop of the car ② The speed at which the vehicle coasts half the distance from the start of braking to the stop ③ The distance from the start of braking to the stop when the sliding speed is half of the initial speed
(1) 2 * (- 4) * s = - 10 ^ 2 from 2As = 0-v0 ^ 2, s = 12.5m (2) 2 * (- 4) * 6.25 = VT ^ 2-10 ^ 2, VT = 5 times the root sign 2 (3) 2As = VT ^ 2-v0 ^ 2, 2 * (- 4) * s = (10 / 2) ^ 2-10 ^ 2, s = 9.375m pay attention to the conversion of units
RELATED INFORMATIONS
- 1. A vehicle traveling along a flat and straight road has a speed of 36km / h. The acceleration obtained after braking is 4m / S2. Find: (1) Speed at the end of 3S after braking; (2) The speed at which the vehicle coasts half the distance from the start of braking to the stop
- 2. An object moves in a straight line with uniform acceleration, the initial velocity is 0.5m/s, and the displacement in the 7th s is 4m more than that in the 5th s Find: (1) the magnitude of the acceleration a of the uniformly accelerated motion of the object (2) The displacement of the object in the first 5S
- 3. Find the transformation relationship between the initial three trigonometric functions sin Tan cos. For example, sin40 is equal to Cos 50
- 4. Solving indefinite integral ∫ 1 / (2x-3) ^ 2DX by substitution method
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- 6. Friction force F and sin α cos α Reference relation of equal trigonometric function That is, when to use sin when the inclination angle on the inclined plane has F α Or cos α For example, what does f = mgcosa mean, and what is the difference between uphill and downhill angles?
- 7. Someone estimated the acceleration of the train with a watch. He observed it for 3min and found that the train had advanced 540M. After 2min, he observed it for 1min and found that the train had advanced 1620m If the train moves in a straight line with uniform acceleration within 6min, the speed of the train is? A.0.01m/s ² B.0.1m/s ² C.0.6m/s ² D.1.8m/s ²
- 8. A train is 200 meters long and passes through a 1.8 km tunnel. It takes 2 minutes to calculate the train speed To be more detailed, there must be known, unit conversion,
- 9. A 200m long train passed the bridge. It was measured that it took 1 minute for the train to get off the bridge. The duration of the whole train on the bridge was 40s. Calculate the length of the bridge and the speed of the train
- 10. An object starts to move in a straight line with uniform acceleration from rest. The acceleration is A1. The movement time is T1. Then it moves in a uniform deceleration with acceleration A2. After T2, the speed is exactly zero. Then the average speed of the object in the whole process can be expressed as? Why are 0.5a1t1 and 0.5a2t2 also right
- 11. When an object moves in a straight line with uniform deceleration, the initial speed is 10 meters per second and the acceleration is 1 meter per second square, what is the average speed of the object 2 seconds before it stops?
- 12. Some students took the power train to travel. When the train accelerated evenly on a straight track, one student proposed, "can we use the equipment around us to measure the acceleration of the train?" many students participated in the measurement. The measurement process was as follows: they looked out of the window every 100m While recording the time with a watch, they observed that the time interval from the first landmark to the second landmark is 5S, and the time interval from the first landmark to the third landmark is 9s. Please find out according to their measurement: (1) Acceleration of train; (2) The speed at which they reached the third sign
- 13. The two trains leave from station a and station B at the same time. The average passenger train travels 90 kilometers per hour and the average freight train travels 75 kilometers per hour. After () hours, two trains leave Meet 30 kilometers from the midpoint of the two stations
- 14. You travel for a week on vacation. The sum of the days of the week is 84. What date did the travel agency send you home?
- 15. The train runs along the track straight line from ground a to ground B. the distance between B is s. The train starts from ground a and accelerates uniformly. The linear motion acceleration is A1, then decelerates uniformly. The linear motion acceleration is A2. When it arrives at B, it just stands still. Calculate the time t for the train from a to B
- 16. A 100 meter long train passes through an iron bridge at the speed of 36 km / h. The time required for all trains to pass through the iron bridge is 50 seconds. What is the total length of the iron bridge?
- 17. It takes 20 seconds for a train to travel at a constant speed through a 450m long tunnel. There is a lamp on the tunnel, and the light shines on the train for 5S Find: (1) the length of the train; (2) The time when the train is completely in the tunnel There is a lamp in the tunnel. The time when the light shines on the train is 5S. What do you mean ////////
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- 19. It takes 65 seconds for a train to pass through a 1000 meter bridge and 50 seconds if it passes through a 730 meter tunnel at the same speed. Find the forward speed and length of the train
- 20. A 200m long train passes through a 1.6km long bridge at a constant speed of 120s, and the running speed of the train is () A. 15m/s B. 11.7m/s C. 1.7m/s D. 13.3m/s