Two cars A and B travel along the same road in the same direction from the same starting point. Car A maintains a speed of 60 km/h and car B is at 75 km/h. But car B started one hour later. How many hours will B take to overtake A?
Thank you to Arslan Chandio for the A2A!Unfortunately there’s no single equation to calculate this in a way similar to the SUVAT equations as far as I know, so I’ll be using logic to pick this problem apart initially.So, given that Car A is travelling at 60 km/h and travels for an hour before Car B starts, we can use distance = speed * time to calculate he distance Car A is ahead of Car B the exact moment Car B begins moving.speed = 60 kilometres per hourtime = 1 hourdistance = 60 * 1distance = 60 kilometresHence, Car A is exactly 60 kilometres ahead of Car B when Car B begins moving.As Car B is travelling 15 kilometres per hour faster than Car A (75 - 60 = 15), we simply have to calculate the time it will take to cover 60 kilometres at 15 kilometres per hour.Using the same equation as previously, except this time we’re working out time instead of distance:speed = 15 kilometres per hourdistance = 60 killmetres60 = 15 * timetime = 60 / 15time = 4 hoursTherefore, it will take Car B 4 hours to catch up to and overtake Car A.
Two cars are traveling along a straight line in the same direction..PHYSICS DUE SOON, HELP?
We will use 2 equations for constant acceleration: V = V0 + at Where, V = final velocity, V0 = initial velocity, a = acceleration, t = time X = V0t + ½ at^2 Where, x = distance, V0 = initial velocity, a = acceleration, t = time First, we need to calculate a time for the lead car to stop: V = V0 + at (V – V0)/a = t (0 – 25m/sec) / (-2.05 m/sec^2) = 12.19 seconds Now, to find the distance, we plug the time required to stop into the second equation: X = V0t + ½ at^2 X = (25m/sec)(12.19 sec) + 0.5(-2.05 m/sec^2)(12.19 sec)^2 X = 152.44 m It will take the lead car 152.44 meters to stop the car Now, we know that the second car has a total of 152.44 + 40 = 192.44 meters to stop the car because the second car was 40 meters behind the lead car at the time the lead car began to stop. We can use the distance equation to solve for the minimum acceleration: X = V0t + ½ at^2 192.44 m = (30.6 m/sec)(12.19 sec) + 0.5a(12.19 sec)^2 192.44 m = 373m + (74.3 sec^2)a (192.44m – 373m) / 74.3 sec^2 = a -180.56m/74.3sec^2 = a = -2.43 m/sec^2 The second car needs to have a minimum acceleration of -2.43 m/sec^2 Now, we can plug this acceleration into the velocity equation to determine the time required to stop V = V0 + at 0 = 30.6 m/sec + (-2.43 m/sec^2) t (-30.6 m/sec) / (-2.43 m/sec^2) = t = 12.59 seconds It will take the second car 12.59 seconds to stop the car.
Can I change my direction and still have a constant velocity?
By definition, when you change direction, you change velocity, even if your speed remains the same, because velocity is a VECTOR, not just a SCALAR quantity. However, most people are usually referring to the speed of the object which remains constant, and then once it is travelling in the desired new direction, they switch back to its velocity. But that new velocity is technically different than the original velocity, because the direction has changed, unless I do a complete circle!However, because velocity is a vector, we can still break it down into its vector components along various directions. If you define the velocity of interest as the vector in the original direction of travel, then as you change direction of motion, there clearly can still be a component of the velocity in that original direction. Indeed you would have to travel perpendicular to your original direction to reduce that original component of velocity to zero.Since the magnitude of that original component of velocity will obviously change as the object changes direction, then you would have to accelerate (or decelerate depending on the initial conditions) to maintain that component of velocity as a constant.So, given the above limitations….yes…it is possible.
Why can two cars in different directions be traveling at the same speed but not at the same velocity?
Speed is a scalar — a quantity that specifies magnitude without direction. Both cars can be moving at 20 m/s, but this does not say anything about their direction.Velocity is a vector — a quantity that contains information on both magnitude and direction. If the cars are moving in exactly the opposite direction (180 degrees apart), then one car will be moving at 20 m/s while the other is moving at -20 m/s. Which car has positive velocity depends on what axis you define as the positive direction.Since velocity is defined as the instantaneous change in position with respect to time (dx/dt), it makes sense that a change in magnitude (speed) and a change in direction would both affect velocity since both direction and speed will result in a change in position.
Why doesn't an airplane traveling in the opposite direction of the Earth's rotation move faster than one traveling in the same direction of the Earth's rotation?
Contrary to what everyone else is saying, it does take longer to fly east that it does to fly west.Its called the Coriolis effect, and it only applies to rotating reference frames.This is why examples of driving in a car and tossing a ball, or walking the length of a ship while its underway, dont apply. Those aren't rotating reference bodies.The air mass of the atmosphere does spin in relative synch with the earth, which is why your airspeed doesn't register differently, but it has nothing to do with the length of the trip.Ignoring things like the jet stream and assuming you were flying in a perfectly static air mass, a trip from NY to LA would take less time than the return trip from LA to NYC if the pilot were flying the same airspeed. But the ground speed will be different in those cases.When you fly west from NYC, LA is physically getting closer to you due to the rotation of the earth while you are in the air. The reverse is true flying east. NYC is constantly moving away from you while you are en route to it.The reason you dont notice is that the pilots have a schedule to keep and a flight plan to stay on. If its supposed to take them 4 hours each way, they adjust the speed of the plane so they get there in 4 hours. They do this because gates have to be empty and waiting, air traffic control is expecting you at a certain time, you have to meet other connecting flights……ect.Compound this in the real world with things like moving air masses and the jet stream, which over N America can sometimes make it faster to fly east ( or much more fuel efficient) and the effect of the Coriolis force is lost in the noise. But it is still there and very real.So real in fact that snipers have to account for it when taking long shots. A sniper shooting while facing N, E, S or W has to account for the fact that the target will have moved several feet due to the spinning of the earth during the few seconds the bullet is in the air. A few feet is not much, but its enough to make you miss if you dont factor it in.
Using Newton's laws, predict what will happen when a car traveling on an icy road...?
Newton's first law of motion (or law of inertia) is the one involved here. It says that an object always has the tendency to remain in its initial state of motion. a) When a car traveling on an icy road comes to a sharp bend, the car will skid outward as it turns. b) But if the car has to stop quickly before reaching the bend, it will not immediately stop moving but it will continue to move fro a while along the original direction of motion.
What are three ways a ride(rollercoaster) can change a person's velocity?
Velocity is a vector, so that it has direction and magnitude (speed). A rollercoaster (or anything) can change either of these or both at the same time. 1. Constant speed with a change in direction 2. Constant direction (straight line) with a change in speed 3. Change in direction and change in speed. Hope this helps!
Question about velocity and acceleration! Please help!?
Okay Question 1) Yes - remeber velocity is speed with direction - so if you define one direction to be possotive and the car is moving in the opp direction it is having a negative velocity, if the car is travelling faster as each second goes by then its acceleration is posotive as its speed is increasing. No the cars velocity cant change signs if its travelling at a constant velocity, a = change in velocity (with a we dont worry too much about direction) if velocity is constant then when you do the change you will get 0 therefore velocity cant change signs. Question 2) Yes, velocity = speed + direction, if the direction changes but its doing the same speed then you have a velocity change : Example - Suppose a rock is falling down with constant acceleration, but magically it changes direction with no loss of acceleration then its velocity has changed as direction has changed. Hope that helps!
How fast can a Formula One car go on a 90-degree turn?
Observe the numbers in circles 1, 8 and 13 at this pic.On number 1, there is a relative short straight before the left turn, but also a long run after the turn. So cars can reach 290 kph and then slow until 127 kph there, a 90 degree left turn. Cars can have a medium speed there because there is a second long run just after the turn.On number 8, however, there is a left-right and very little space. Also, cars have reached 316 kph just before, so the cars deaccelerate abruptly and then make a weaving move. Only 81 kph at this turn.11, 12, and 13 are very short runs, so the car starts to accelerate at turn 11 and doesn’t need to brake at 12, so keeps rising speed. By the time they turn left on 13, they are at 128 hph.As a conclusion, it depends on both the previous straight and the following ones. I decided to show you the Abu Dhabi Circuit as it’s plenty of 90-degree turns and the asphalt is the same.And it’s very, very boring.