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3 years ago

12

A stone dropped from a bridge strikes the water 2.2 s later. How high is the bridge above thewater

1 answer:

mina [271]3 years ago

7 0

Since you are giving no information whatsoever, the formula could be:

S = (1/2)g.t², where s is the distance, 9 =9.8 m/s² and t = time
S = (1/2).(9.8)(2.2)² ans S= 23.7 meters

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salantis [7]

Answer:

where is the table

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

A teacher places n seats to form the back row of a classroom layout. Each successive row contains two fewer seats than the prece

Alex_Xolod [135]

Answer:

The number of seat when n is odd $S_n=\frac{n^2+2n+1}{4}$

The number of seat when n is even $S_n=\frac{n^2+2n}{4}$

Step-by-step explanation:

Given that, each successive row contains two fewer seats than the preceding row.

Formula:

The sum n terms of an A.P series is

$S_n=\frac{n}{2}[2a+(n-1)d]$

$=\frac{n}{2}[a+l]$

a = first term of the series.

d= common difference.

n= number of term

l= last term

$n^{th}$ term of a A.P series is

$T_n=a+(n-1)d$

n is odd:

n,n-2,n-4,........,5,3,1

Or we can write 1,3,5,.....,n-4,n-2,n

Here a= 1 and d = second term- first term = 3-1=2

Let $t^{th}$ of the series is n.

$T_n=a+(n-1)d$

Here $T_n=n$ , n=t, a=1 and d=2

$n=1+(t-1)2$

⇒(t-1)2=n-1

$\Rightarrow t-1=\frac{n-1}{2}$

$\Rightarrow t = \frac{n-1}{2}+1$

$\Rightarrow t = \frac{n-1+2}{2}$

$\Rightarrow t = \frac{n+1}{2}$

Last term l= n,, the number of term $=\frac{ n+1}2$ , First term = 1

Total number of seat

$S_n=\frac{\frac{n+1}{2}}{2}[1+n}]$

$=\frac{{n+1}}{4}[1+n}]$

$=\frac{(1+n)^2}{4}$

$=\frac{n^2+2n+1}{4}$

n is even:

n,n-2,n-4,.......,4,2

Or we can write

2,4,.......,n-4,n-2,n

Here a= 2 and d = second term- first term = 4-2=2

Let $t^{th}$ of the series is n.

$T_n=a+(n-1)d$

Here $T_n=n$ , n=t, a=2 and d=2

$n=2+(t-1)2$

⇒(t-1)2=n-2

$\Rightarrow t-1=\frac{n-2}{2}$

$\Rightarrow t = \frac{n-2}{2}+1$

$\Rightarrow t = \frac{n-2+2}{2}$

$\Rightarrow t = \frac{n}{2}$

Last term l= n, the number of term $=\frac n2$ , First term = 2

Total number of seat

$S_n=\frac{\frac{n}{2}}{2}[2+n}]$

$=\frac{{n}}{4}[2+n}]$

$=\frac{n(2+n)}{4}$

$=\frac{n^2+2n}{4}$

4 0

3 years ago

Please help me please

VLD [36.1K]

Answer:

A for the second part

2/1

Step-by-step explanation:

an inequality is a comparison.

3 0

3 years ago

Let f (x)=-3x+ determine f (-5)

loris [4]

F(x)=-3x
f(-5)=-3* (-5)
=15

hope ths help u !!!!!!!!!

^_^

6 0

3 years ago

Pls help me with this

alexgriva [62]

Answer:

x = 1.5

Step-by-step explanation:

Given

$\frac{x}{2} \geq 0.75$

$\frac{x}{2} < 2.5$

Required

Find the value of x.

First, the inequalities need to be rewritten and merged;

if $\frac{x}{2} \geq 0.75$ , then

$0.75 \leq \frac{x}{2}$

Multiply both sides by 2

$2 * 0.75 \leq \frac{x}{2} * 2$

$1.5 \leq x$

Similarly;

$\frac{x}{2} < 2.5$

Multiply both sides by 2

$2 * \frac{x}{2} < 2.5 * 2$

$x < 5$

Merging these results together; to give

$1.5 \leq x < 5$

This means that the range of values of x is from 1.5 to 4.9999....

From the question, x is the smallest rational number; from the range above ( $1.5 \leq x < 5$ ), the minimum value of x is 1.5 and 1.5 is a rational number;

Hence, x = 1.5

4 0

3 years ago