Advertisements
Advertisements
प्रश्न
A body projected vertically up with a velocity of 10 m/s reaches a height of 20 m. If it is projected with a velocity of 20 m/s, then the maximum height reached by the body is:
पर्याय
20 m
10 m
80 m
40 m
Advertisements
उत्तर
80 m
Explanation:
Initial velocity = u = 10 m/s
Height = Distance = S = 20 m
At highest point, Final velocity = v = 0
Acceleration = (a) = ?
Case − I
v2 − u2 = 2aS
(0)2 − (10)2 = 2a (20)
a = `-100/40` = −2.5 ms−2
Case – II
u = 20 m/s; v = 0
a = −2.5 ms−2; S = h /
v2 − u2 = 2aS
(0)2 − (20)2 = 2(−2.5)h
h = `400/5` = 80 m
APPEARS IN
संबंधित प्रश्न
What does the odometer of an automobile measure?
During an experiment, a signal from a spaceship reached the ground station in five minutes. What was the distance of the spaceship from the ground station? The signal travels at the speed of light, that is, 3 × 108m s−1.
Fill in the following blank with suitable word:
The physical quantity which gives both, the speed and direction of motion of a body is called its……………
If a sprinter runs a distance of 100 metres in 9.83 seconds, calculate his average speed in km/h.
The speed of a moving object is determined to be 0.06 m/s. This speed is equal to :
One of the following is not a vector quantity. This one is :
Give an example of the motion of a body moving with a constant speed but with a variable velocity. Draw a diagram to represent such a motion.
Express the following in m s−1.
1 km h−1
A car is moving in a straight line with speed 18 km h-1. It is stopped in 5 s by applying the brakes. Find:
- the speed of car in m s-1
- the retardation and
- the speed of car after 2 s of applying the brakes.
Define speed of a body.
