Beth drives 200 miles in 4 hours. she drives the first 18 miles at an average speed of 36 mph. work out her average speed for the rest of the

The average speed for the rest of the journey is 52miles per hour.

Given that,

Beth drives 200miles in 4 hours ,

She drives the first 18 miles at an average speed of 36 mph.

We have to find,

Her average speed for the rest of the journey.

According to the question,

She drives the first 18 miles at an average speed of 36 mph.  

Here, distance = 18 miles

Speed = 36 mph

Then, Distance = speed × time

18miles = 36mph × time

Time = =

Time is half an hour.

Now,

Remaining distance = 200 - 18 = 182miles

And time use for remaining journey = hours.

Putting the value in the equation

182miles = average speed × hours.

Average speed = = 52miles per hour

Hence, The average speed for the rest of the journey is 52miles per hour.

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Beth travelled the remaining distance with an average speed of 52 mph

Solution:

Given, Beth drives 200 miles in 4 hours.  

The formula for distance speed is given as:

  --- eqn 1

Calculating time taken for 18 miles:

She drives the first 18 miles at an average speed of 36 mph.  

Here distance = 18 miles

speed = 36 mph

Plugging in values in eqn 1 we get,

Calculating average speed for the rest of the journey:

Now, remaining distance = 200 miles – 18 miles = 182 miles

And time used for remaining journey = total time – time taken for first 18 miles

Plugging in values in eqn 1, we get

Thus the average speed for rest of journey is 52 mph

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w