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3 years ago

Why does a stop sign appear red?

Physics

1 answer:

dolphi86 [110]3 years ago

8 0

Answer:

because it’s suppose to be red like a stop light.

Explanation:

So it tells you to stop

You might be interested in

What does the slope on a speed vs. time graph represent

steposvetlana [31]

Answer:

It represents the amount of speed per time or (x) for speed (y) for time so the slope would be like y/x

5 0

3 years ago

Cars A and B are racing each other along the same straight road in the following manner:

zysi [14]

Answer:

$\frac{x_{o}}{v_B-V_A} =t$

Explanation:

Represent the car's position as a function

$x_o=$ "head start"

$x_{A}(t) = x_{o} + v_{A}t\\x_B(t)=v_Bt \\$

$Remember: v_B>v_A$

"cathching up means" that $x_A(t)=x_B(t)$

$x_{o} + v_{A}t =v_Bt\\x_{o} = v_Bt -v_{A}t\\x_{o} = t(v_B-V_A)\\\frac{x_{o}}{v_B-V_A} =t, where \ v_B>v_A$

8 0

3 years ago

A centrifuge rotates so that 0. 25 m from the center is traveling at 343 m/s (the speed of sound). How many RPM is this? What is

andrew-mc [135]

Answer:

[13,101 RPM]

[1372 rad/s]

Explanation:

8 0

2 years ago

A light rope is attached to a block with mass 3.60 kg that rests on a frictionless, horizontal surface. The horizontal rope pass

Readme [11.4K]

Answer and Explanation:

(a) The fre-body diagrams for each block is shown below. In the block of mass 3.60 kg, there are 3 forces acting on it: horizontal force due to the rope ( $F_{t}$ ), vertical gravitational force ( $F_{g}$ ) and vertical normal force ( $F_{n}$ ), due to the surface. Since there is no vertical movement, $F_{g}$ and $F_{n}$ cancels it out. So, for this block, net force is horizontal due to the rope $F_{t}$ .

The block of mass m is hanging from the pulley, so there is the force of the rope ( $F_{t}$ ) and the gravitational force ( $F_{g}$ ). Both are vertical, because there is no surface "holding" block m.

(b) Since both blocks are attached to each other, the acceleration will be the same. To calculate it, we use the Second Law of Motion:

$F_{r}=m.a$

$a=\frac{F_{r}}{m}$

$a=\frac{18.8}{3.6}$

a = 5.22

The acceleration of either block is 5.22 m/s².

(c) Block m has 2 forces acting on it: tension and gravitational force. Gravitational force is the force of attraction the Earth does over an object. It is calculated as the product of mass and gravitational acceleration, which has magnitude g = 9.8 m/s².

Suppose positive referential is going up. To determine mass:

$F_{r}=m.a$

$F_{t}-F_{g}=m.a$

$F_{t}-m.g=m.a$

$18.8-9.8m=5.22m$

$15.02m=18.8$

m = 1.25

Block m has 1.25 kg.

(d) Gravitational force is also called weight. So, as described above: $F_{g}=m.g$ .

The weight for the hanging block is

$F_{g}=1.25*9.8$

$F_{g}=$ 12.25 N

Comparing tension and weight:

$\frac{12.25}{18.8}$ ≈ 0.65

We can see that, weight of the hanging block is almost 0.65 times smaller than the tension on the rope.

4 0

3 years ago

One difference between mixture and pure substances is that

Lunna [17]

Pure substances can be elements made up exclusively of one kind of atom, or they can be compounds made up of molecules that include two or more elements. Mixtures can be homogeneous or heterogeneous depending on how finely mixed the components are.

7 0

2 years ago