Question

3) A body starts from rest and attains velocity 90km/h in 1min.Find acceleration and force if mass is 1200kg​

Answer 1

GIVEn

A body starts from rest and attains velocity 90km/h in 1min.

TO FINd

Find acceleration and force if mass is 1200kg

SOLUTIOn

• Initial velocity (u) = 0
• Final velocity (v) = 90km/h
• Time (t) = 1 min = 60 sec
• Acceleration (a) = ?

→ v = 90km/h

→ v = 90 × 5/18

→ v = 25m/s

**Apply formula**

→ v = u + at

→ 25 = 0 + a × 60

→ 25 = 60a

→ a = 25/60 = 0.4m/s²

_____________________

• Mass (m) = 1200kg
• Acceleration (a) = 0.4m/s²
• Force (F) = ?

**Apply formula**

→ F = m × a

→ F = 1200 × 0.4

→ F = 480 N

Therefore, Acceleration of body is

0.4m/s²

And Force of body is 480 N

Answer 2

Answer:

Explanation:

Given :-

Initial velocity, u = 0 (As body starts from rest)

Final velocity, v = 90 km/h = 90 × 5/18 = 25 m/s

Time taken, t = 60 seconds.

To find :-

Acceleration, t = ??

Force if mass = 1200 kg

Formula to be used :-

1st equation of motion, i.e, v = u + at

Force = mass × acceleration

Solution :-

Putting all the values, we get

v = u + at

⇒ 25 = 0 + a × 60

⇒ 25 = 60a

⇒ 25/60 = a

⇒ a = 0.4 m/s²

Now force, F

Force = mass × acceleration

⇒ Force = 1200 × 0.4

⇒ Force = 480 Newton.

Hence, the acceleration is 0.4 m/s² and force is 480 Newton.