Advertisements
Advertisements
Question
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:
Options
20 m
10 m
80 m
40 m
Advertisements
Solution
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
RELATED QUESTIONS
What is the Differnece between speed and velocity ?
Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging?
- from A to B and
- from A to C?
What name is given to the speed in a specified direction ?
A motorcyclist drives from place A to B with a uniform speed of 30 km h-1 and returns from place B to A with a uniform speed of 20 km h-1. Find his average speed.
If a bus travelling at 20 m/s is subjected to a steady deceleration of 5 m/s2, how long will it take to come to rest ?
Which of the following can sometimes be 'zero' for a moving body?
(i) average velocity
(ii) distance travelled
(iii) average speed
(iv) displacement
Give one example of following motion :
Uniform velocity
A train takes 2 h to reach station B from station A, and then 3 h to return from station B to station A. The distance between the two stations is 200 km. Find:
The average speed,
The average velocity of the train.
The velocity-time graph of a moving body is given below in Figure
Displacement in each part AB, BC and CD.
What is the relation between distance and time when the body is moving with variable velocity?
