Question

1. A car starts from rest and accelerates uniformly for 8.0 s. It reaches a final speed of 16 ms-
b What is the average velocity of the car?​

Answer 1

Solution :—

Given :-

• Initial Velocity (u) = 0 m/s
• Final Velocity (v) = 16 m/s
• Time Taken (t) = 8 s

To Find :-

• Average Speed

Firstly, we need to find acceleration and after calculating acceleration we can calculate distance covered and then finally find out the average speed

So, let's solve it out further

Calculating Acceleration

Formula Used :-

• v = u + at

⟹ 16 = 0 + a × 8

⟹ 16 = 0 + 8a

⟹ 16 = 8a

⟹ 8a = 16

⟹ a = 16/8

⟹ a = 2

Thus, the acceleration is 2 m/s²

Calculating Distance Covered

Formula Used :-

• v² - u² = 2as

⟹ (16)² - (0)² = 2 × s

⟹ 256 - 0 = 2s

⟹ 2s = 256

⟹ s = 256/2

⟹ s = 128

Thus, the Distance Covered is 128 m

Now, Calculating Average Speed :-

Formula Used :-

• Average Speed = Total Distance/Total Time

⟹ 128/8

⟹ 88

Thus, the Average Speed is 88 m/s

Hence, Solved ♡

Answer 2

Answer:

Note that the expert verified answer is wrong as it forgot to multiply the 2 of acceleration from the 2 of the 2as while finding this distance with the help of  v^2-u^2=2as. therefore the expert verified answer isn't correct. You can try it for yourself, here is the corrected version of it,

v^2-u^2=2as

16^2-0^2=2x2xs

256-0=4s

256/4=s

s=64

finding the acceleration-

using v=u+at

16=0+ax8

a=2ms^-2

finding the distance

using s=ut+1/2at^2

s=0x8+1/2x2x8^2

s=0+64

s=64m

average velocitity=total displacement/total time

average velocitity=64/8

average velocitity=8ms^-2

Thank you, done with love

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