Advertisements
Advertisements
Question
Multiple choice Question. Select the correct option.
A body dropped from the top of a tower reaches the ground in 4s. Height of the tower is
Options
39.2 m
44.1 m
58.8 m
78.4 m
Advertisements
Solution
78.4 m
Explanation:
Initial velocity = u = 0
Time = t = 4s
As body falls downards,
so acceleration = a = + g = a = + 9.8 ms−2
(Distance) S = ut + 1/2 at
S = (0) (4) + 1/2 × 9.8 × (4)3
s = 0 + 1/2 × 9.8 × 16
S = 9.8 × 8 = 78.4 m
APPEARS IN
RELATED QUESTIONS
Which of the two can be zero under certain conditions : average speed of a moving body or average velocity of a moving body ?
Name the physical quantity whose SI unit is :
(a) m/s (b) m/s2
What conclusion can you draw about the velocity of a body from the displacement-time graph shown below :
Find the initial velocity of a car which is stopped in 10 seconds by applying brakes. The retardation due to brakes is 2.5 m/s2.
A train travelling at 20 m s-1 accelerates at 0.5 m s-2 for 30 s. How far will it travel in this time ?
Derive the formula : v = u + at, where the symbols have usual meanings.
A car acquire a velocity of 72 km per hour in 10 second starting from rest. Find
(1) the acceleration,
(2) the average velocity, and
(3) the distance travelled in this time.
For a uniformly retarded motion, the velocity-time graph is _____________
Multiple choice Question. Select the correct option.
The speed of a car reduces from 15 m/s to 5 m/s over a displacement of 10 m. The uniform acceleration of the car is :
A girl walks along a straight path to drop a letter in the letterbox and comes back to her initial position. Her displacement–time graph is shown in Fig.8.4. Plot a velocity-time graph for the same.
