Question

Suhasini purchased the following items from a Handloom store. (1) 2 bedsheets, $360 each (ii) 2 floormats,
120 each. She received a rebate of 15%. Find the total rebate and the amount paid by Suhasini for the
purchase.
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Answer 1

Answer:

Answer:

Angular retardation of flywheel = π/10  rad/s²

Explanation:

Given:-

Initial angular velocity of flywheel = 360 rpm

Final angular velocity of flywheel = 180 rpm

Time taken for change in angular velocity = 1 min = 60 sec

To find:-

Angular acceleration (retardation) of the flywheel, a =?

Formula required:-

Formula for angular acceleration

        a = Δω / Δt

[ where a is angular acceleration, Δω is change in angular velocity, Δt is change in time ]

Solution:-

Converting the angular velocities given in rpm into rad/sec

→ ω₁ = 360 rpm = 360 × 2π/60  rad/sec = 12π rad/sec

→ ω₂ = 180 rpm = 180 × 2π/60  rad/sec = 6π rad/sec

Calculating the angular acceleration

→ a = Δω / Δt

→ a = (12π - 6π) / (60)

→ a = -6π / 60

→ a = -π/10  rad/s²

Therefore,

Angular retardation of the flywheel is π/10  rad/s².

Answer 2

Cost of one bed sheet is 375

Cost of 2 bedsheets 750

Cost of one floor mat 525

Cost of 2 floor mats 1050

Total cost is 1800

Rebate amount is 10015×1800=270

so he pays 1800−270=1530