Question

A body travels 200 cm in the first 2 s and 220 cm in the next 5 s. Calculate the velocity at the end of the seventh second from the start.​

Answer 1

Answer:

10 cm/s

Step-by-step explanation:

s=ut+  $\frac{1}{2}$$at^{2}$

 

For case 1.

200=2u+2a

u+a=100....(1)

For case 2. .i.e. next 4 seconds, we have distance =420 cm and time =6 s

420=6u+18a

u+3a=70....(2)

Solving equation 1 and 2, we get,  

u=115 cm/s and a=−15 cm/s  

2

 

Now by  

v=u+at

v=115−15×7

v=10 cm/s