All categories

3 years ago

Which boxes represent pure substances?

Physics

2 answers:

anygoal [31]3 years ago

7 0

D only because the rest are all compounds and even though for c they are not connected they are still included to be compounded

Mademuasel [1]3 years ago

3 0

A, B and D can I have Brainlyest thx

You might be interested in

Mike is cutting the grass using a human-powered lawn mower. He pushes the mower with a force of 45 n directed at an angle of 41Â

Andrej [43]

Answer:

work done will be equal to 305.05 J

Explanation:

We have given force exerted F = 45 N

Angle with the horizontal $\Theta =41^{\circ}$

Distance moved due to exerted force d = 9.1 m

Work done is equal to $W=Fcos\Theta \times d$ , here F is force $\Theta$ is angle with horizontal and d is distance moved due to force

So work done $W=45\times cos41^{\circ}\times 9.1=309.05J$

So work done will be equal to 305.05 J

7 0

3 years ago

How to find a planet’s gravitational field strength using its radius?

grin007 [14]

The gravitational field strength is approximately equal to 10 N.

<u>Explanation:</u>

Gravitational field strength is the measure of gravitational force acting on any object placed on the surface of the planet. Generally, the mass of the object is considered as 1 kg.

So the gravitational field strength will be equal to the gravitational force acting on the object.

The formula for gravitational field strength is

$g = \frac{F}{m}$

Here g is the gravitational field strength, m is the mass of the object placed on the surface and F is the gravitational force acting on the object.

Since, the mass of any object placed on the surface of earth will be negligible compared to the mass of Earth, so the mass of the object is considered as 1 kg.

Then the g = F

And $F =\frac{GMm}{r^{2} }$

Here G is the gravitational constant, M is the mass of Earth and m is the mass of the object placed on the surface, while r is the radius of the Earth.

$g = F = \frac{6 \times 10^{24} \times 6.67 \times 10^{-11} \times 1}{(6.6 \times 10^{6}) ^{2} }$

$g = 0.977 \times 10^1= 9.77\ N$

So, the gravitational field strength is approximately equal to 10 N.

5 0

2 years ago

Find the equivalent resistance Req between terminals a and b if terminals c and d are open and again if terminals c and d are sh

adoni [48]

Answer:

351 ohm

720 ohm

Explanation:

When c and d are open:

Terminals c and d are open.. If you redraw the circuit as below, you can see that the two resistors in the first column are in parallel as, they are connected together at both pairs of terminals (due to the short).

Hence, we have a pair of parallel resistors:

Req1 = (R1*R2)/ (R1 + R2) = 360*540/(360+540) = 216 ohms

Req2 = (R3*R4)/ (R3 + R4) = 180*540/(180+540) = 135 ohms

Now these two sets are in series with another Hence,

Req = Req1 + Req2 = 216 + 135 = 351 ohms

Answer: 351 ohms

When c and d are shorted:

The current will flow through the least resistant path naturally from resistors R3 and R1 or R4.

Both of these resistor lie in a single path placing the resistors in series to one another, hence

Req = R3 + R1 = 180 + 540 = 720 ohms

Answer:720 ohms

7 0

2 years ago

A 40kg kid riding their bike down the street at 5m/s reaches the edge of a hill and coast down to the bottom. If the hill was 10

Romashka [77]

Answer

vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv

Explanation:v

6 0

3 years ago

Which is a property of light a: mass b: density c: wavelength d: pitch

Reptile [31]

Im pretty sure its C- Wavelength

6 0

2 years ago