A train 400 m long is moving on a straight track with a speed of 84.8 km/h. The engineer applies the brakes at a crossing, and later the last car passes the crossing with a speed of 16.2 km/h. Assuming constant acceleration, determine how long the train blocked the crossing. Disregard the width of the crossing.

Q: A person takes a trip, driving with a constant speed of 95.5 km/h, except for a 24.0-min rest stop.…

A: (a) Expression for total time travelled

Q: Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P…

A: velocity of car A at point P = 136 km/hr velocity of car A after 4.6 sec = 100 km/hr initial…

Q: External stimuli are communicated to the brain by means of electrical signals propagating along…

A: speed of electrical signals along nerve cells (v) = 34 m/s distance travelled by signal resulting…

Q: A subway train starts from rest at a station and accelerates at a rate of 2.50 m/s? for 15.90…

A:

Q: (a) What is the magnitude of the average acceleration of a skier who, starting from rest, reaches a…

A:

Q: A jetliner, traveling northward, is landing with a speed of 72.1 m/s. Once the jet touches down, it…

A: Given data:  Initial velocity (v0) = 72.1 m/s Final velocity (v) = 5.71 m/s Displacement (d) = 806 m…

Q: A man walks on sand at speed 1.20 m/s over a distance of 48.0 m, after which he walks on pavement…

A: Given :- speed on sand = 1.20 m/s distance = 48 m walk on pavement = 102 m  average speed of entire…

Q: A skier left a mountain 40 m long in 10 s, after which he rode along a horizontal platform to a stop…

A: The acceleration of skier is 0.8 m when it just left the mountain. The velocity when skier reach at…

Q: At the instant the traffic light turns green, an automobile starts with a constant acceleration a of…

A: Given: acceleration of automobile aa=2.3 m/s2 constant speed of truck ut=vt=9.6 m/s

Q: Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P…

A:

Q: This is a practice problem that I'm pretty sure I got correct. I got that she rode 3388 meters on…

A: Given that:During first part of trip:Distance of first trip is given by:During second part…

Q: At the moment of departure of a train, the signalman is standing next to the first wagon, which…

A: Answer            63.6 Sec

Q: A person takes a trip, driving with a constant speed of 93.0 km/h except for a 22.0-min rest stop.…

A:

Q: Dr. John Paul Stapp was a U.S. Air Force officer who studied the effects of extreme acceleration on…

A: Given data: Initial speed is, u1=0 m/s                  (As sled starts from rest) Final speed is,…

Q: A train 400 m long is moving on a straight track with a speed of 82.4 km/h. The engineer applies the…

A: Given: Length of train S = 400 m or 0.4 km Initial velocity vi = 82.4 kmh Final velocity vf = 16.4…

Q: A person travels by car from one city to another with different constant speeds between pairs of…

A: (a) Average speed is,

Q: g at a location where the speed limit is 100 km/h. The police officer in car P observes this speed…

A:

Q: A motorcycle has a constant acceleration of 2.83 m/s². Both the velocity and acceleration of the…

A: Acceleration of motorcycle (a) = 2.83 m/s2

Q: The driver of a car is initially moving at a constant speed of 70.4 km/h when a traffic light turns…

A: Initial speed of the car is V = 70.4 km/h  Reaction time is t = 0.520 s

Q: Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P…

A:

Q: To qualify for the finals in a racing event, a race car must achieve an average speed of 160 mi/hr…

A:

Q: A person travels by car from one city to another with different constant speeds between pairs of…

A: (a) The time taken to travel from one city to another city is

Q: Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P…

A:

Q: An athlete swims the length of a 41.0-m pool in 15.0 s and makes the return trip to the starting…

A:

Q: Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P…

A: The car is initially travelling at a speed of 127 km/h, as soon as it passes the police car, it…

Q: Raindrops fall 1.06 x 103 m from a cloud to the ground. If they were not slowed by air resistance,…

A:

Q: Chapter 4- questn-30 The velocity of a particle moving in the xy plane is defined by i = (6.0t –…

A:

Q: An automobile travels on a straight road for 40 km at 30 km/hr speed. It then continues in the same…

A: The speed of the car in a distance of , The speed of the car in the next ,

Q: A car is moving in constant motion along the positive x-direction on a straight and level road. For…

A: the average velocity of the car is ,   vav-x=x2-x1t2-t1

Q: A jetliner, traveling northward, is landing with a speed of 57.5 m/s. Once the jet touches down, it…

A:

Q: Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P…

A:

Q: car was traveling at 33.0 m/s on a poorly lit country road.  The driver started to brake 0.35…

A: The distance travelled by the car is, d=vt=33 m/s0.35 s=11.55 m The distance between the bridge and…

Q: In a test run, a certain car accelerates uniformly from zero to 21.6 m/s in 2.15 s. (a) What is the…

A: Given Data: Initial velocity of car (u) = 0 m/s Final velocity of car (v) = 21.6 m/s time (t) = 2.15…

Q: At 5:11 p.m. in the highway and at the height of a town, a police patrol was traveling at a speed of…

A: (a)   Consider the time taken by police petrol to reach the citizen after the reaction time be t.…

Q: Car A is traveling at a location where the speed limit is 100 km/h. The police officer in car P…

A:

Q: (a) What is the magnitude of the average acceleration of a skier who, starting from rest, reaches a…

A:

Relative Velocity

It is a measurement of an object with regards to the other object which is moving or stable or stationary. For example, if we are traveling in a bus and the bus is moving at speed of 50km/hr, then our speed is according to the nearby passenger on the bus is zero. According to them, we are not moving. But if one person standing on the ground or road observes us from outside of the bus, according to him we are moving at a speed of 50km/hr and the bus is also moving at a speed of 50km/hr. Now, the motion is recognized by the observer, it depends on a frame of reference or observer. This is motion called relative motion.