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3 years ago

13

A parcel of mass 10 kg rests on a lorry.When the lorry accelerates at 1.5 m/s^2,the parcel is just about to slide backwards. Wha

t is the co-efficient of friction between the parcel and the lorry?

1 answer:

Mademuasel [1]3 years ago

5 0

Answer:

The coefficient of static friction, μ = 0.153

Explanation:

Given data,

The mass of the parcel, m = 20 kg

The acceleration of the lorry, a = 1.5 m/s²

The normal force acting on the parcel,

f = m x g

= 20 x 9.8

= 196 N

The static frictional force acting on the lorry,

F = 20 x 1.5

= 30 N

The coefficient of static is

μ = F / f

= 30 / 196

= 0.153

Hence, the coefficient of static friction, μ = 0.153

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A power supply has an open-circuit voltage of 40.0 V and an internal resistance of 2.00 $\Omega$ . It is used to charge two storage batteries connected in series, each having an emf of 6.00 V and internal resistance of 0.300 $\Omega$ . If the charging current is to be 4.00 A, (a) what additional resistance should be added in series? At what rate does the internal energy increase in (b) the supply, (c) in the batteries, and (d) in the added series resistance? (e) At what rate does the chemical energy increase in the batteries?

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Explanation:

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The internal resistance is $R = 2 \Omega$

The emf of each battery is $e = 6.00 V$

The internal resistance of the battery is $r = 0.300V$

The charging current is $I = 4.00 \ A$

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