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3 years ago

Which of the following is not a vector

Physics

2 answers:

kaheart [24]3 years ago

7 0

The answer is b length

Komok [63]3 years ago

4 0

Length is not a vector because you only need to state a unit (etc. meters, centimetres, or feet) and not a direction

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High-speed stroboscopic photographs show that the head of a 210-g golf club is traveling at 56 m/s just before it strikes a 46-g

tamaranim1 [39]

Explanation:

It is given that,

Mass of golf club, m₁ = 210 g = 0.21 kg

Initial velocity of golf club, u₁ = 56 m/s

Mass of another golf ball which is at rest, m₂ = 46 g = 0.046 kg

After the collision, the club head travels (in the same direction) at 42 m/s. We need to find the speed of the golf ball just after impact. Let it is v.

Initial momentum of golf ball, $p_i=m_1u_1=0.21\ kg\times 56\ m/s=11.76\ kg-m/s$

After the collision, final momentum $p_f=0.21\ kg\times 42\ m/s+0.046v$

Using the conservation of momentum as :

$p_i=p_f$

$11.76\ kg-m/s=0.21\ kg\times 42\ m/s+0.046v$

v = 63.91 m/s

So, the speed of the golf ball just after impact is 63.91 m/s. Hence, this is the required solution.

3 0

3 years ago

The pressure in a traveling sound wave is given by the equation ΔP = (1.78 Pa) sin [ (0.888 m-1)x - (500 s-1)t] Find (a) the pre

frozen [14]

Answer:

a) $P_m=1.78\ Pa$

b) $f=79.5775\ Hz$

c) $\lambda=7.076\ m$

d) $v=563.06\ m.s^{-1}$

Explanation:

<u>Given equation of pressure variation:</u>

$\Delta P= (1.78\ Pa)\ sin\ [(0.888\ m^{-1})x-(500\ s^{-1})t]$

We have the standard equation of periodic oscillations:

$\Delta P=P_m\ sin\ (kx-\omega.t)$

<em>By comparing, we deduce:</em>

(a)

amplitude:

$P_m=1.78\ Pa$

(b)

angular frequency:

$\omega=2\pi.f$

$2\pi.f=500$

∴Frequency of oscillations:

$f=\frac{500}{2\pi}$

$f=79.5775\ Hz$

(c)

wavelength is given by:

$\lambda=\frac{2\pi}{k}$

$\lambda=\frac{2\pi}{0.888}$

$\lambda=7.076\ m$

(d)

Speed of the wave is gives by:

$v=\frac{\omega}{k}$

$v=\frac{500}{0.888}$

$v=563.06\ m.s^{-1}$

8 0

3 years ago

2. True or False Every sample of a pure substance has exactly the same composition

Marrrta [24]

Answer:

the correct answer is False

Explanation:

i hope its right

5 0

2 years ago

1. seesaw

Sergeeva-Olga [200]

Answer:

1 seesaw = first class lever

2. pencil and sharpener = wheel and axle

3. bottle opener = second class lever

4. forearm = third class lever

5. nail = wedge

Explanation:

The given objects are classic examples of simple machines.

Lever: There are 3 types of levers and they depend on where the load, applied force, and fulcrum are.

First class levers have the fulcrum in between the load and the applied force. In other words, the load and applied force are at opposite ends. The seesaw is a good example of this. Other examples would be, pliers, scissors, and the like.

Second class levers have the fulcrum and the applied force at the opposite ends. So in this case, the load is found in between. Examples of this would be a bottle opener or a crowbar.

For third class levers, the load and the fulcrum are at opposite ends and the applied force is in between. The forearm is a good example, so is a stapler, or even a broom.

A wedge is another simple machine. It is thick at one end and it gets thinner towards the other end, or it usually has a sharp end. Other examples of this would be an axe, or a knife.

A sharpener is actually a compound machine. The old-fashioned type of pencil sharpener, the one you crank makes use of a wheel and axle and a wedge. A wheel and axle is usually a machine that makes use of two circular parts; a wheel and a rod that is attached to its center.

4 0

3 years ago

Molecular clouds range in mass from a few times the mass of our Sun (solar masses) to 10 million solar masses. Individual stars

babymother [125]

Answer:

Explained in Depth.

Explanation:

It is all matter of what kind of stars are we talking about, for simplicity let's say we are talking about normal stars such as our sun.

If there is a molecular cloud that has a mass that is slightly larger than our sun then it is possible that the gravity will eventually pull together cloud into a sphere that would have enough mass to start nuclear fusion which is important to become a star.

Mass of such cloud would be 1.98x10^30Kg almost equal to the sun's mass.

All of this implies that stars are formed when there is enough mass to let gravity pull it all together into a sphere that has enough gravitational pull to start nuclear fusion inside the core.

3 0

3 years ago