Advertisements
Advertisements
प्रश्न
An artificial satellite is moving in a circular orbit of radius 42250 km. Calculate its speed if it takes 24 hours to revolve around the earth.
Advertisements
उत्तर
Radius of circular orbit = 42250 km
= 42250 × 1000 m
Time taken for one revolution = 24 hours
= 24 × 60 × 60 s
speed = `"distance"/"time"`
= `(2 pi r)/"time"`
= `2 xx 22/7 xx (42250 xx 1000)/(24 xx 60 xx 60)`
= 3073.74 m s−1
= 3.07 km s−1
APPEARS IN
संबंधित प्रश्न
A trolley, while going down an inclined plane, has an acceleration of 2 cm s−2. What will be its velocity 3 s after the start?
A racing car has a uniform acceleration of 4 m s−2. What distance will it cover in 10 s after start?
A ball is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate of 10 m s−2, with what velocity will it strike the ground? After what time will it strike the ground?
Multiple choice Question. Select the correct option.
A driver applies brakes when he sees a child on the railway track, the speed of the train reduces from 54 km/h to 18 km/h in 5 s. What is the distance travelled by train during this interval of time?
A boy drops a stone from a cliff, reaches the ground in 8 seconds. Calculate
- final velocity of stone
- height of cliff. (Take g = 9.8 ms−2)
A stone thrown vertically upwards takes 4 s to return to the thrower. Calculate
- initial velocity of the stone
- maximum height attained by stone. (Take g = 10 ms−2)
A spaceship is moving in space with a velocity of 50 kms−1. Its engine fires for 10 s, such that its velocity increases to 60 kms−1. Calculate the total distance travelled by a spaceship in 1/2 minute, from the time of firing its engine
Derive the equations
(i) v= u+at and
(ii) v2-u2= 2as, where the symbols have their usual meanings.
A body starts to slide over a horizontal surface with an initial velocity of 0.5 ms−1. Due to friction, its velocity decreases at the rate of 0.05 ms−2. How much time will it take for the body to stop?
A train is moving at a speed of 90 km/h. On applying brakes, a retardation of 2.5 ms-2 is created. At what distance before, should the driver apply the brakes to stop the train at the station?
