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3 years ago

Please help with 3 questions about acceleration

Physics

1 answer:

Goryan [66]3 years ago

5 0

A great, helpful, useful definition of acceleration is

A = (change in speed) / (time for the change) . <== you should memorize this

This simple tool will directly solve all 3 problems.

The REASON for assigning these problems for homework is NOT to find the answers. It's to help YOU find out whether you know this definition, to let you go back and review it if you don't, and to give you a chance to practice using it if you do. Noticed that if you get the answers from somebody else, you lose all of these benefits.

The only wrinkle anywhere here is in #3, because when you use this definition, the unit of time has to be the same in both the numerator and the denominator.

So for #3, you have to EITHER change the km/hr to km/sec, OR change the 4sec to a fraction of an hour, before you plug anything into the definition.

You might be interested in

Magnetic fields are caused by?

zaharov [31]

The motion of an electric charge producing a magnetic field is an essential concept in understanding magnetism. The magnetic moment of an atom can be the result of the electron's spin, which is the electron orbital motion and a change in the orbitalmotion of the electrons caused by an applied magnetic field.

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3 years ago

Jerry the mouse is running along a straight desert road at a constant velocity of 18 m/s. If a certain Tom cat wants to capture

Kruka [31]

Answer:

a) t = 1.75 s

b) x = 31.5 m

Explanation:

a) The time at which Tom should drop the net can be found using the following equation:

$y_{f} = y_{0} + v_{oy}t - \frac{1}{2}gt^{2}$

Where:

$y_{f}$ : is the final height = 0

y₀: is the initial height = 15 m

g: is the gravity = 9.81 m/s²

$v_{0y}$ : is the initial vertical velocity of the net = 0 (it is dropped from rest)

$0 = 15m - \frac{1}{2}9.81 m/s^{2}*t^{2}$

$t = \sqrt{\frac{2*15 m}{9.81 m/s^{2}}} = 1.75 s$

Hence, Tom should drop the net at 1.75 s before Jerry is under the bridge.

b) We can find the distance at which is Jerry when Tom drops the net as follows:

$v = \frac{x}{t}$

$x = v*t = 18 m/s*1.75 m = 31.5 m$

Then, Jerry is at 31.5 meters from the bridge when Jerry drops the net.

I hope it helps you!

3 0

2 years ago

What is the maximum speed when the conditions are mass =450 kg, initial height= 30 m, and the roller coaster is initially at res

Zarrin [17]

Answer:

B. 24.2 m/s

Explanation:

Given;

mass of the roller coaster, m = 450 kg

height of the roller coaster, h = 30 m

The maximum potential energy of the roller coaster due to its height is given by;

$P.E_{max} = mgh\\\\PE_{max} = 450 *9.8*30\\\\PE_{max} = 132,300 \ J$

$P.E_{max} = K.E_{max} \ (law \ of \ conservation\ of \ energy)$

$K.E_{max} = \frac{1}{2}mv_{max}^2\\\\ v_{max}^2 = \frac{2K.E_{max}}{m}\\\\ v_{max}^2 = \frac{2*132300}{450}\\\\ v_{max}^2 =588\\\\v_{max} = \sqrt{588}\\\\ v_{max} = 24.2 \ m/s$

Therefore, the maximum speed of the roller coaster is 24.2 m/s.

3 0

2 years ago

In a water molecule, which atom has the strongest attraction for shared electrons?

ra1l [238]

Oxygen... Hope this Warner helps

6 0

3 years ago

Read 2 more answers

Suppose that the angular separation of two stars is 0.1 arcseconds, and you photograph them with a telescope that has an angular

Crank

Answer: the photograph will likely show only one star.

Explanation:

Since their angular separation is smaller than the telescope's angular resolution, the picture will apparently show only one star rather than two.

4 0

2 years ago