(ii) Round off the number of seconds in an hour to 1 significant figure.
4000

A plane travels at a speed of 212 mph.
b) By rounding 212 to 1 significant figure and using your answer
to part (ii), work out an estimate for the number of seconds the plane
takes to travel 1 mile.

Total marks: 4

The number of seconds in an hour to 1 significant figure is 1.1111.

The number of seconds the plane  takes to travel 1 mile is 16.98 seconds.

We have to determine, the number of seconds in an hour to 1 significant figure.

And the number of seconds the plane  takes to travel 1 mile.

According to the question,

1. Number of seconds = 4000

The number of seconds in an hour is,

Therefore,

The number of seconds in an hour to 1 significant figure.

Hence, The number of seconds in an hour to 1 significant figure is 1.1111.

2. A plane travels at a speed of 212 mph,

The number of seconds in an hour is,

Therefore,

The number of seconds the plane  takes to travel 1 mile is,

Hence, The number of seconds the plane  takes to travel 1 mile in 16.98 seconds.

For more details refer to the link given below.

link

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Step-by-step explanation:

(ii)

Given 4000 seconds to hours you divide the value by 3600 sec

=4000/3600 =1.1111

=1.0 hour (1 significant figure)

(b)

speed = 212 miles/hour

distance= 1 mile

time = distance/speed = 1/212 * 3600 =16.98 seconds