physics question?

Question

A flatbed truck is traveling at 50 mph with its ramp down. A chase car follows behind at 55 mph and drives up the ramp. When the tires contact the ramp will it rocket forward or gradually climb the ramp?

Answer 1

It will gradually climb the ramp. When the car is doing a steady 55, there is no acceleration. The engine is just providing enough force to overcome air friction. For the car to suddenly accelerate rapidly would require the engine to suddenly produce an extreme force.

Answer 2

The car is travelling at a steady speed of 55 mph in a horizontal plane behind the truck moving at 50 mph. The open ramp behind the truck is surely at an angle to the horizon. Imagine the situation when the car is poised with its back wheel still on the ground and the rest of the car [front wheel, body, etc] already upon the ramp. This implies that the component of the car speed along the ramp angle is greater than or equal to the truck speed i.e. 50 mph. Therefore the car can climb the ramp only if the ramp angle 'a' satisfies the equation 55Cos'a' >= 50. if these two are just equal, the car will just climb up the ramp smoothly and stay just there. If its speed is less, it cannot climb the ramp at all. If its speed is more, it will climb the ramp with a jerk, move up quickly and dash against the truck body.

Answer 3

In all likelihood, the tires would lose their grip against the ramp and start burning rubber. But assuming that doesn't happen, the car would begin to accelerate as it goes up the ramp. If you are on the ramp watching it, it would appear to start out at 5 mph and accelerate quickly (how fast depends on the strength of the engine). From an observation point on the side of the road, it will start at 55 mph and accelerate towards 105. It won't immediately hit 105 mph because of inertia and because it will be going uphill. And it will probably hit the cab of the truck before it has a chance to reach 105 mph. But yeah, if the truck was reeeeeeaaallly long, then the car would reach a speed of 105 mph (i.e. 55 mph with relation to the truck).

The reason it would accelerate rather than staying at 5 mph with relation to the ramp is because I am assuming that the driver has his foot on the gas pedal in a "55 mph" position. If this was a friction-less cart with no engine, it would actually decelerate, because it would be losing kinetic energy as it went up the ramp. In this case, it would either go partway up the ramp and then roll back down, ending up on the road moving at 45 mph instead of 55, or it would make it up the ramp, but would be moving at some speed between 55 and 50 mph, depending on the height of the ramp.

Answer 4

Think about this. It's all about relative speed. If you're standing in the middle of the truck you're not moving.....right? Not with respect to the truck, but you are with the road, assuming the truck is traveling down the road.

Ok, now, if you take off from the back of the trailer on a motorcycle you'd slam into the front of the trailer before you had a chance to stop.

Ok now.....so what's the difference between this and driving up on a ramp into a trailer going 55 mph?

Once the car gets on the trailer it's going to be moving at 55 mph with respect to the trailer......so it's going to be moving pretty fast, and more than likely you'll crash before you have a chance to stop.

It's about the speeds of the truck and car and which is relative to what. When you are in your car the speedometer is recording the speed at the wheel. It doesn't care if you're on a road, or in a trailer. When the car reaches the ramp the speed will then be relative to the trailer, not the road, so you will be essentially on a motionless platform (trailer) moving at 55 mph.

Answer 5

Both vehicles are travelling 50 and 55 relative to the pavement. As soon as the car tires hit the truck ramp, the car is travelling 5 relative to the truck, and it would gain at 7.3 feet/second.
Think of a car and a tow truck. The truck tows the car at 50 mph, both relative to the pavement, but the car's speed relative to the truck is zero. If the car was suddenly put in gear and speeds up to 55 (relative to pavement), it would move closer to the truck.
Another example: Two cars travelling side by side at 70mph. Is it possible to transfer an object between the two cars? Yes , the speed of one car relative to the other is zero. Its no more difficult than if the cars were parked.

Answer 6

rocket forward. The deal is this - the drive wheels are spinning at 55 mph relative to the pavement. Transfer that motion to another platform and the drive wheels will still spin at the same speed.

Transfer to a moving platform and the Lorentz transformation will take effect, and velocities will be combined. Your car's wheels will spin at 55 mph relative to the truck's platform, which is also traveling 50 mph.

To demonstrate this at a lower order of magnitude, try the moving walkways found in many airports. When you walk onto or off of these movers, you have that jolt of extra speed, particularly if you are walking off at a decent rate of speed.

Answer 7

The majority of the chase car's inertia is only going 5mph faster than the flatbed. The spinning wheels that are driving the car have a low moment of inertia compared to the car. When the faster spinning wheels hit the ramp, you will feel them bite, but the wheels de-spinning will result in a little nudge.

Answer 8

Its going to climb up the ramp gradually because the velocity of truck is already 50mph, the car which is travelling at a velocity of 55mph, has an extra velocity of 5mph. that will be the speed it would go up the ramp. so, the car moves up the ramp at a speed of 5mph, which is going up gradually.
Hope u got it. good luck. Bye

Answer 9

It will rocket forward.

The ramp is seen as standing still to the front drive wheels of the car. It will accelerate to a combined speed of 105mph.

Answer 10

Its not going to go 110 mph suddenly.