Advertisements
Advertisements
Question
How long will a stone take to fall to the ground from the top of a building 80 m high
Solution
Height, s = 80m
g = 10 m/s2
Using the second equation of motion,
S = ut + (1/2) gt2
Or, 80 = 0+ (1/2) (10) (t) 2
Or, (t) 2 = 16
Or, t = 4s
APPEARS IN
RELATED QUESTIONS
Two blocks A and B of mass mA and mB , respectively, are kept in contact on a frictionless table. The experimenter pushes block A from behind, so that the blocks accelerate. If block A exerts force F on block B, what is the force exerted by the experimenter on block A?
Suppose the ceiling in the previous problem is that of an elevator which is going up with an acceleration of 2.0 m/s2. Find the elongation.
Use Newton's second law of motion to explain the following instance :
A cricketer pulls his hands back while catching a fast moving cricket ball .
The correct form of Newton's second law is :
A stone is dropped freely from the top of a tower and it reaches the ground in 4 s. Taking g = 10m s-2, calculate the height of the tower.
A pebble is dropped freely in a well from its top. It takes 20 s for the pebble to reach the water surface in the well. Taking g = 10 m s-2 and speed of sound = 330 m s-1. Find : The time when echo is heard after the pebble is dropped.
What do you mean by linear momentum of a body?
In the previous problem (5.3), the magnitude of the momentum transferred during the hit is ______.
A woman throws an object of mass 500 g with a speed of 25 ms1.
- What is the impulse imparted to the object?
- If the object hits a wall and rebounds with half the original speed, what is the change in momentum of the object?
Figure shows (x, t), (y, t ) diagram of a particle moving in 2-dimensions.
|
|
 (b) |
If the particle has a mass of 500 g, find the force (direction and magnitude) acting on the particle.
