Question

plese solve the above questions it's urgent please
don't spam !!!!​

Answer 1

ExPlanation:

From question we have,

• Speed of A = 36 km/h = 10 m/s
• Speed of B & C = 54 km/h = 15 m/h

[Note: I have converted them in m/s because we need to find acceleration which is in m/s², so anyway if you will not convert it here, you will have to futher on]

Now,

You see, A & C will come together at a point B must have its speed higher than of A & C;

• Speed of A & C combined = 10 + 15 = 25 m/s

From question, I know there must be 1 km of distance between A & C, so time taken:

• Time = Distance/Speed
• Time = 1000/25 [ 1km = 1000 m]
• Time = 40 sec

So, yeah B must have a speed so as it can overtake A within 40 sec, but wait whatt about the distance?? there you go;

• Distance = Time × Speed
• Distance = 10 × 40
• Distance = 400 m

{If u are confused why have I taken speed as 40? then gurI, remember B has to take over A right, so we will see the distance covered on the basis of A only}

And after this much huge calculation, atlast we can say that the distance B has to cover is,

• Distance = [Distance between B & A] + [Distance A will cover after those 40 sec]
• Distance = 1000 + 400
• Distance = 1400 m

Don't loose patience, we are just done, so I have d,s,u of B so yeah! You guessed it right we will use 2nd equation if motion:

• S = ut + ½at²
• 1400 = 15 × 40 + ½ × a × (40)²
• 1400 = 600 + 800a
• 1400 - 600 = 800a
• 800 / 800 = a
• 1 m/s² = a

Therefore, finally Car B has to make a minimum acceleration of 1m/s² to overtake Car A.

___________________________________