Ask question

Ask question

All categories

3 years ago

15

Two spheres of the same size and mass roll down an incline. Sphere A is hollow and Sphere B is solid with uniform density. Which

reaches the bottom of the incline first?
Make sure to EXPLAIN your answer!

(a) Sphere A
(b) Sphere B
(c) At the same time.

1 answer:

sweet [91]3 years ago

8 0

If the spheres are have to have the same and the same size, it is expected that they will have the same surface area. The only factor that affects the descent of the object through gravity on Earth is the surface area that is exposed to the resistance of air. For this case, it is expected that they will reach the bottom of the inclined plane together. The answer is C.

You might be interested in

As light from a star spreads out and weakens, do gaps form between the photons?<br>

Zolol [24]

Answer:

There are no gaps in space between the photons as they travel. If you were to look at a wave then you'd come to a conclusion that indeed that there aren't any gaps unless they are specifically placed.The light from a distance star indeed spreads out and weakens as it travels, but this just reduces the wave strength and does not introduce gaps.

3 0

3 years ago

A car of mass 1000.0 kg is traveling along a level road at 100.0 km/h when its brakes are applied. Calculate the stopping distan

OleMash [197]

Explanation:

It is given that,

Mass of the car, m = 1000 kg

Speed of the car, v = 100 km/h = 27.77 m/s

The coefficient of kinetic friction of the tires, $\mu_k=0.5$

Let f is the net force acting on the body due to frictional force, such that,

$-f=ma$

$a=\dfrac{-f}{m}$

$a=\dfrac{-\mu _k mg}{m}$

$a=\mu_k g$

$a=-0.5\times 9.8$

$a=-4.9\ m/s^2$

We know that the acceleration of the car in calculus is given by :

$v.dv=a.dx$ , x is the stopping distance

$\int\limits^0_v {v.dv}=\int\limits^x_0 {a.dx}$

$\dfrac{v^2}{2}|_v^0=ax$

$0-(27.77)^2=-2\times 4.9x$

On solving the above equation, we get, x = 78.69 meters

So, the stopping distance for the car is 78.69 meters. Hence, this is the required solution.

6 0

3 years ago

AVprozaik [17]

Answer: I put the importance of the lab in the topic is to find how dense an object is and if it can sink or float and it's important to answer the question so you can also find mass and volume.

Explanation: I dunno haha...

8 0

3 years ago

An aluminum bar 600mm long with diameter 40mm, has a hole drilled in the center of the bsr.The hole is 30mm in diameter and is 1

marta [7]

Answer:

<em>1.228 x </em> $10^{-6}$ <em> mm </em>

<em></em>

Explanation:

diameter of aluminium bar D = 40 mm

radius of aluminium bar R = D/2 = 40/2 = 20 mm

diameter of hole d = 30 mm

radius of the hole r = d/2 = 30/2 = 15 mm

compressive Load F = 180 kN = 180 x $10^{3}$ N

modulus of elasticity E = 85 GN/m^2 = 85 x $10^{9}$ Pa

length of bar L = 600 mm

length of hole = 100 mm

true length of bar = 600 - 100 = 500 mm

area of the bar A = $\pi r^{2}$ = 3.142 x $20^{2}$ = 1256.8 mm^2

area of hole a = $\pi (R^{2} - r^{2})$ = $3.142* (20^{2} - 15^{2})$ = 549.85 mm^2

Total contraction of the bar = $\frac{F*L}{AE} + \frac{Fl}{aE}$

total contraction = $\frac{F}{E} * (\frac{L}{A} +\frac{l}{a})$

==> $\frac{180*10^{3}}{85*10^{9}} *( \frac{500}{1256.8} + \frac{100}{549.85})$ = <em>1.228 x </em> $10^{-6}$ <em> mm </em>

8 0

3 years ago

All of the following are true of models except

BARSIC [14]

I did this.
If your answers look like this...
a. <span>models have the ability to communicate </span>
<span>b. </span><span>models have the ability to correctly predict all outcomes </span>
<span>c. </span>model have the ability to test predictions
<span>d. </span><span>models have the ability to save time
</span>Then it's D

4 0

3 years ago