Question

a bullet of mass of 0.01kg fired from a gun hits a wooden plank witha a velocity 400 m/s and emerges out with a velocity 100m/s calculate the force by a plank to the motion of the bullet if the the thickness of the plank is 0.05m​

Answer 1

Answer:

Average resistive force is= mass (m) x a

=8000N

Step-by-step Explanation:

Initial velocity u =300m/s

Final velocity v= 100m/s

Distance s=0.05m

Retartdation be a

2xaxs= v²- u?

2xax0.05= 100x100 - 300x300

a= 800000

Average resistive force is= mass (m) x a

=8000N

Answer 2

Given

• Mass(Bullet) = 0.01 Kg
• Initial Velocity = 400 m/s
• Final Velocity = 100 m/s
• Thickness (Plank) = 0.05 m

To Find

• Force applied by the plank

Solution

☯ v²-u² = 2as

• We shall use this third Equation of motion to find the acceleration of the body

☯ F = ma

• We shall us this formula to find the Force applied and hence the Answer!!

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✭ According to the Question :

→ v²-u² = 2as

→ 100²-400² = 2 × a × 0.05

→ 10000 - 160000 = 0.1a

→ -150000 = 0.1a

→ -150000/0.1 = a

→ Acceleration = -1500000 m/s²

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✭ Force Applied :

→ F = ma

→ F = 0.01 × -1500000

→ F = -15000 N

• Note that the Force applied is negative as it is a force that is applied against the motion of the bullet