Home
Class 12
PHYSICS
A roller coaster is designe such that ri...

A roller coaster is designe such that riders experience "weightlessness" as they go round the top of a hill whose radius of curvature is 20m. The speed of the car at the top of the hill is between

A

16 m/s and 17 m/s

B

13 m/s and 14 m/

C

14 m/s and 15 m/s

D

15 m/s and 16 m/s

Text Solution

Verified by Experts

The correct Answer is:
C
`ng-N=(mv^(2))/(r)`

When N = 0, for weightlessness
`(mv^(2))/(r)=mg`
`rArr upsilon^(2)=rg=20xx10=200`
`upsilon=14.14`
Promotional Banner

Similar Questions

Explore conceptually related problems

A roller coaster is designed such that riders experience "weightlessness" as they go round the top of a hill whose radius of curvature is 20m . The speed of the car at the top of the hill is between

A car moves at a constant speed on a straigh but hilly road. One section has a crest and dip of the 250m radius. (a) As the car passes over the crest the normal force on the car is half the 16kN weight of the car. What will the noraml force on the car its passes through th ebottom of the dip? (b) What is the greatest speed at which the car can move without leaving the road at the top of the hill ? (c) Moving at a speed found in part (b) what will be the normal force on the car as it moves through the bottom of the dip? (Take, g=10m//s^(2))

Two guns situated at the top of a hill of height 10 m fire one shot each with the same speed 5sqrt(3) m//s at some interval of time. One gun fires horizontal and the other fores upwards at an angle of 60^(@) with the horizontal. Two shots collide in air at a point P . Find (i) time-interval between the firing and (ii) coordinates of the point P . Take the origin of coordinates system at the foot of the hill right below the muzzle and trajectorise in the x-y plane.

A small toy car moves round a circular track of radius 4 m. The car makes one revolution in 10 s. Calculate (a) the speed of the car, (b) its centripetal acceleration, (c) the centripetal force exerted,by the track if the.mass of the car is 200 g, (d) the safe speed with which the car can move around without toppling, if the distance between the wheels is 4 cm and the height of the centre of gravity of the car from the horizontal is 2 cm.

Two guns situated at the top of a hill of height 10 m fire one shot each with the same speed 5sqrt(3) m//s at some interval of time. One gun fires horizontal and the other fores upwards at an angle of 60^(@) with the horizontal. Two shots collide in air at a poit P . Find (i) time-interval between the firing and (ii) coordinates of the point P . Take the origin of coordinates system at the foot of the hill right below the muzzle and trajectorise in the x-y plane.

A train is moving with a speed of 20 m/s at a place where the radius of curvature of the railway line is 1500 m. Calculate the distance between the rails if the elevation of the outer rail above the inner rail is 0.042 m ?

Name the type of waves which are used for line of sight (LOS) communication. What is the range of their frequencies? A transmitting antenna at the top of a tower has a height of 20m and the height of the receiving antenna is 45m. Calculate the maximum distance between them for satisfactory communication in LOS mode. (Radius of the Earth = 6.4 xx 10^(6) m)

A car travelling towards a hill at 10 m//s sound its horn which a frequency 500 H_(Z) . This is heard in a second car travelling behind the first car in the same direction with speed 20 m//s . The sound can also be heard in the second car by reflections of sound the hill. The beat frequency heard by the driver of the sound car will be (speed of sound in air = 340 m//s)

A block of mass m at the end of a string is whirled round in a vertical circle of radius R. The critical speed of the block at top of its swing below which the string would slacken before the block reaches the bottom is?