We read your photo as:

A clock has second and minute hands of lengths 7.5 cm and 6.0 cm respectively. What is the ratio of the distance covered by the tip of the minute hand in 30 minutes to that covered by the tip of the second hand in 30 minutes?

Mathematics

ScanSolve AI Answer

Answer

139.4 m\text{139.4 m}

Step-by-step solution

6 steps
  1. Identify the given information and the goal.

    Given:

    • Length of second hand, rs=75 cmr_s = 75 \text{ cm}
    • Length of minute hand, rm=60 cmr_m = 60 \text{ cm}
    • Time duration, T=30 minutesT = 30 \text{ minutes}
    • Value of π=3.14\pi = 3.14

    Goal: Find the difference xx in the distance traveled by the tip of the second hand and the tip of the minute hand in meters.
    x=Distancesecond hand−Distanceminute handx = \text{Distance}_\text{second hand} - \text{Distance}_\text{minute hand}

  2. Convert the time duration to seconds.

    T=30 minutes×60 seconds/minute=1800 secondsT = 30 \text{ minutes} \times 60 \text{ seconds/minute} = 1800 \text{ seconds}
  3. Calculate the angular speed of each hand.

    The angular speed (ω\omega) is given by ω=2πPeriod\omega = \frac{2\pi}{\text{Period}}.

    • For the second hand: It completes one full revolution (2π\pi radians) in 60 seconds.
    ωs=2π rad60 s=π30 rad/s\omega_s = \frac{2\pi \text{ rad}}{60 \text{ s}} = \frac{\pi}{30} \text{ rad/s}
    • For the minute hand: It completes one full revolution (2π\pi radians) in 60 minutes.
    ωm=2π rad60 min=2π rad3600 s=π1800 rad/s\omega_m = \frac{2\pi \text{ rad}}{60 \text{ min}} = \frac{2\pi \text{ rad}}{3600 \text{ s}} = \frac{\pi}{1800} \text{ rad/s}
  4. Calculate the angle rotated by each hand in T=1800T = 1800 seconds.

    The angle rotated (θ\theta) is given by θ=ωT\theta = \omega T.

    • For the second hand:
    θs=ωsT=(π30 rad/s)×(1800 s)=60π rad\theta_s = \omega_s T = \left(\frac{\pi}{30} \text{ rad/s}\right) \times (1800 \text{ s}) = 60\pi \text{ rad}
    • For the minute hand:
    θm=ωmT=(π1800 rad/s)×(1800 s)=π rad\theta_m = \omega_m T = \left(\frac{\pi}{1800} \text{ rad/s}\right) \times (1800 \text{ s}) = \pi \text{ rad}
  5. Calculate the distance traveled by the tip of each hand.

    The distance traveled (arc length, LL) is given by L=rθL = r\theta.

    • For the second hand:
    Ls=rsθs=(75 cm)×(60π rad)=4500π cmL_s = r_s \theta_s = (75 \text{ cm}) \times (60\pi \text{ rad}) = 4500\pi \text{ cm}
    • For the minute hand:
    Lm=rmθm=(60 cm)×(π rad)=60π cmL_m = r_m \theta_m = (60 \text{ cm}) \times (\pi \text{ rad}) = 60\pi \text{ cm}
  6. Calculate the difference xx and convert it to meters.

    x=Ls−Lm=4500π cm−60π cmx = L_s - L_m = 4500\pi \text{ cm} - 60\pi \text{ cm} x=(4500−60)π cm=4440π cmx = (4500 - 60)\pi \text{ cm} = 4440\pi \text{ cm}

    Substitute π=3.14\pi = 3.14:

    x=4440×3.14 cm=13941.6 cmx = 4440 \times 3.14 \text{ cm} = 13941.6 \text{ cm}

    Convert centimeters to meters (1 m=100 cm1 \text{ m} = 100 \text{ cm}):

    x=13941.6100 m=139.416 mx = \frac{13941.6}{100} \text{ m} = 139.416 \text{ m}

    The approximate value of xx is 139.4 m.

    The final answer is 139.4 m\text{139.4 m}.

Was this helpful?

Try one yourself

A new problem that tests the same skill.

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp