A jet aeroplane travelling at the speed of 500 km/h ejects the burnt gases at the speed of 1200 km/h relative to the jet aeroplane. Find the speed of the burnt gases w.r.t. a stationary observer on earth.

A vehicle moving with a speed of 18 km h-^1covers……….m in 1 s.

An aircraft executes a horizontal loop at a speed of 720 km/ h with its wings banked at 15°. What is the radius of the loop?

A car moving with a speed of 126 kmh^-1 is brought to stop within a distance of 200 m. What is its retardation and how long it takes for the car to stop ?

A man walks on a straight road from his home to a market 2.5 km away with a speed of 5 km h ^-1 . Finding the market closed, he instantly turns and walks back home with a speed of 7.5 km h^-1 . What is the average speed of the man over the interval of time (i) 0 to 30 min, (ii) 0 to 50 min, (Hi) 0 to 40. min? [Note: You will appreciate from this exercise why . it is better to define average speed as total path length divided by time, and not as magnitude of average velocity. You would not like to tell the tired man on his return home that his average speed was zero!]

A car moving along a straight highway with a speed of 126 km h^-1 is brought to a stop within a distance of 200 m. What is the retardation of the car (assumed uniform), and how long does it take for the car to stop?

A trolley of mass 200 kg moves with a uniform speed of 36 km/ h on a frictionless track. A child of mass 20 kg runs on the trolley from one end to the other (10 m away) with a speed of 4 m s^-1 relative to the trolley in a direction opposite to the its motion, and jumps out of the trolley. What is the final speed of the trolley? How much has the trolley moved from the time the child begins to run?

The maximum speed of a train is 90 km/h. It takes 10 hours to cover a distance of 500 km. Find the ratio of its average speed to maximum speed?

A car takes 2 hours to reach a destination by travelling at the speed of 60 km/h. How long will it take when the car travels at the speed of 80 km/h?

A train travels at a certain average speed for a distance of 63 km and then travels a distance of 72 km at an average speed of 6km/hour more than its original speed. lf it takes 3 hours to complete the total journey, what is its original average speed?