Q14 of 18 Page 326

State the equations of free fall.


The equations of motion are:
v=u+at
v2=u2+2as
Under free fall, u=0,
a=acceleration due to gravity=g,
s=height of fall=h
Thus under free fall, the equations become
v=gt
v2=2gh

More from this chapter

All 18 →
13

A car falls off a ledge and drops to the ground in 0.5 seconds.

Let g = 10 ms-2, then


(a) What is its speed on striking the ground?


(b) What is its average speed during 0.5 second?


(c) how high is the ledge from the ground?

 14

Define free fall.

 14

Find the velocity with which a ball is thrown up if it reaches the maximum height in 5s. Also find its maximum height.

 15

Raju goes to the vegetable vendor in the market. He notices that the needle of the balance is not in the centre of the balance. He takes the stuff, gets its mass checked in an electric balance and gets back to the vendor asking him to change the balance.

(a) How would you treat the vendor if you were in Raju’s place?


(b) Which values of Raju are noteworthy?


(c) Why is it important to check the weight of substance before buying it?