Which one of the following is NOT considered a part of a forensic scientist's job?

As a science fair project, you want to launch an 800 g model rocket st raight up and hit a horizontally moving target as it pass

fredd [130]

Sum the forces in the y (upward) direction

$\sum F_y = ma$

$F_t +F_w = ma$

$15N - (0.800kg)(9.81m/s^2) = 0.800kg * a$

$a = 8.94 m/s^2$

Applying the kinematic equations of linear motion we have that the displacement as a function of the initial speed, acceleration and time is

$s = v_0t + \frac{1}{2} at^2$

$30 = 0 +\frac{1}{2} (8.94) t^2$

$t = 2.59 s$

Again through the kinematic equation of linear motion that describes velocity as the change of displacement in a given time, we have to

$v = \frac{d}{t} \rightarrow d = vt$

$d = (15m/s)(2.59s)$

$d = 38.85m$

Therefore the horizontal distance between the target and the rocket should be 38.83m

4 0

3 years ago

a man can row about 4kmperhr in a still water.he rows the boat 2km up the stream and 2km back to his starting point in 2hr.how f

Nat2105 [25]

<u>Answer</u>:

The stream flowing at a speed of $2.828 \mathrm{km} / \mathrm{hr}$

<u>Explanation</u>:

Given:

Distance = 2km (both in upstream and downstream)

The speed in still water be x km/hr.

The speed in upstream = 4-x

Speed in downstream = 4+x

Solution:

We know that, Speed = distance/time

So, Time = distance/speed

Therefore,

$2=\left(\frac{2}{4-x}\right)+\left(\frac{2}{4+x}\right)$

$2=\frac{2(4+x)+2(4-x)}{(4-x)(4+x)}$

$2(4-x)(4+x)=2(4+x)+2(4-x)$

$2(4-x)(4+x)=2(4+x+4-x)$

By cancelling 2 on both sides,

$16-x^{2}=8$

$x^{2}=16-8=8$

$x=\sqrt{8}$

$x=2.828 \mathrm{km} / \mathrm{hr}$

Result:

Thus the speed of the stream is $2.828 \mathrm{km} / \mathrm{hr}$

7 0

3 years ago

During what time interval was the object traveling most quickly?

anygoal [31]

ANSWER

0s to 3s

EXPLANATION

To find the time interval where the object was traveling more quickly, we have to find the velocity of the object during each interval.

From a position-time graph, we can obtain the velocity of the object from the slope of the graph in each interval. To find those slopes, we just have to divide the vertical difference by the time interval.

The interval from 0s to 3s:

$v=\frac{7-3}{0-3}=-\frac{4}{3}m/s$

The interval from 3s to 5s and the interval from 7s to 8s have a horizontal line, so the slope is zero and therefore the velocity is zero - meaning that the object was not moving during these periods.

The interval from 5s to 7s,

$v=\frac{5-3}{7-5}=\frac{2}{2}=1m/s$

And the interval from 8s to 12s,

$v=\frac{0-5}{12-8}=-\frac{5}{4}m/s$

Two of these three velocities are negative. Negative velocity indicates that the object is moving backward.

From these velocities, the greatest one, in absolute value, is the one between 0s to 3s. During this interval, the object is moving backward but at the greatest velocity.

3 0

10 months ago

An ideal gas is sealed in a container at constant volume. if the temperature t is increased to 4t, the pressure will be:

Westkost [7]

I believe that it would increase to 4p

6 0

3 years ago

Read 2 more answers

Which of the answer choices is a true statement? Select all that apply. Metallic elements usually exist as molecules, combining

lianna [129]

Metallic elements can exist on their own as individual atoms.

Nonmetals usually exist as molecules, combining with atoms of themselves.

Nonmetals can exist on their own as individual atoms.

Explanation:

Metallic elements can exist on their own as individual atoms. They have a large radius and are stable enough to freely exist as single atoms. The metallic bonding in them gives them stability. Example Gold, Silver, Platinum e.t.c

Non-metals are usually found in combined as state as molecules. They are usually joined together by covalent attraction. The bonds are formed with the atoms shares their valence electrons and their octet is completed. For example nitrogen gas, oxygen gas.

Most noble gases are non-metals that exist as individual mono-atomic gases on their own. The gases are stable and have an octet/duet configuration. For example helium gas, neon gas e.t.c

learn more;

Metals and non-metals brainly.com/question/2758034

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7 0

3 years ago