Directions: Complete the concept map using the terms listed below.

What standard of measurement do most countries use and discuss why such a standard is beneficial

frosja888 [35]

I mean i guess its the metric system?

6 0

3 years ago

A box is sitting on a 2 m long board at one end. A worker picks up the board at the end with the box so it makes an angle with t

Vlada [557]

Answer:

Explanation:

When the box is on the ramp , component of its weight along the ramp

= mg sinθ

Friction force acting on it in upward direction

=μ mg cosθ

For sliding

μ mg cosθ < mg sinθ

μ cosθ < sinθ

.5 x cos35 < sin35

.41 < .57

So the box will slide

When sliding starts , kinetic friction acts

Net force in downward direction

mgsinθ - μ mg cosθ

acceleration

= gsinθ - μ g cosθ

= 5.62 - .3 x 9.8 x cos35

= 5.62 - 2.4

= 3.22 m /s²

3 0

3 years ago

An experiment was devised to investigate the effects on the temperature of a cup of coffee when cream is added at different time

svet-max [94.6K]

Hi Babylilith32,

Your Question:

An experiment was devised to investigate the effects on the temperature of a cup of coffee when cream is added at different time intervals. Hot and cold water were used instead of coffee and cream. First, a container of water heated to 80°C was allowed to sit for 15 minutes. Its temperature was measured at regular intervals. Next, similar temperature measurements were taken for 15 minutes on a new container of heated water, but this time some cold water was added after the 2-minute reading. Finally, the procedure was repeated except that for this last test, the cold water was added after the 12-minute reading. The resulting recorded temperatures were plotted on the graph shown here.

Answers:

1. If you have cool water then you have to add it to the hot water after a few minutes.

2. The independant variable is the cold water

3. The dependant variable is the temperature

4. The control is the hot water without the cold water.

5. The 2 min cold water drops way to much.

7 0

3 years ago

A trap-jaw ant snaps its mandibles shut at very high speed, a good trait for catching small prey. But an ant can also slam its m

irakobra [83]

Answer:

v = 0.509 m/s

Explanation:

Given that,

Mass of the ant, $m = 12\ mg = 1.2\times 10^{-5}\ kg$

Force exerted, $F = 47\ mN = 0.047\ N$

Time, $t=0.13\ ms=0.00013\ s$

To find,

Speed with which it leave the ground.

Solution,

The change in momentum is equal to the product of force and time as :

$F\times t=m(v-u)$

Since, u = 0

$F\times t=mv$

$v=\dfrac{Ft}{m}$

$v=\dfrac{0.047\ N\times 0.00013\ s}{1.2\times 10^{-5}\ kg}$

v = 0.509 m/s

So, the speed with which it will leave the ground is 0.509 m/s.

3 0

3 years ago

A hot–air balloon is moving at a speed of 10 meters/second in the +x–direction. The balloonist throws a brass ball in the +x–dir

IrinaVladis [17]

The ball has an initial speed of 10m/s. This is because it is moving with the balloon. Now the balloonist throws the ball 4m/s with respect to himself, so it means that he gives the ball a extra push of 4m/s, so the total speed is 14m/s. Since it takes 30 seconds to reach the ground, the distance travelled is 14*30=420m.

7 0

3 years ago