The speed of a moving bullet can be determined by allowing the bullet to pass through two rotating paper disks mounted a distance

87 cm apart on the same axle. From the

angular displacement of 21.6◦

of the two bullet holes in the disks and the rotational speed

537 rev/min of the disks, we can determine

the speed of the bullet.

What is the speed of the bullet?

Answer in units of m/s.

Question

Physics

Mathew Hester

12 February, 18:34

The speed of a moving bullet can be determined by allowing the bullet to pass through two rotating paper disks mounted a distance

87 cm apart on the same axle. From the

angular displacement of 21.6◦

of the two bullet holes in the disks and the rotational speed

537 rev/min of the disks, we can determine

the speed of the bullet.

What is the speed of the bullet?

Answer in units of m/s.

+1

Answers (1)

Know the Answer?

Katelyn Fowler · Answer 1

130 m/s

Explanation:

First use the angular displacement to find the time.

Δθ = ω t

21.6° * (1 rev / 360°) = 537 rev/min * (1 min / 60 s) t

t = 0.0067 s

Now use the distance to find the speed.

v = Δx / t

v = 0.87 m / 0.0067 s

v = 130 m/s