All categories

4 years ago

I need physics help!!

Physics

1 answer:

nlexa [21]4 years ago

6 0

Answer: magnitude = 5 and angle = 160°

Explanation:

A vector has magnitude 5 and angle -20°

A vector can be written in terms of its components as :

$\vec{A}=A_x\hat{i}+A_y\hat j \\ \Rightarrow \vec A = A cos\theta \hat i+A sin\theta \hat j$

using trigonometry identity:

sin θ = -sin ( 180 + θ )

cos θ = - cos (180 + θ)

Thus, we can write the same vector as:

$\vec A = -A cos(180+\theta) \hat i+(-A) sin(180+\theta) \hat j$

Magnitude $|A|=\sqrt{(-A)^2+(-A)^2} = A = 5$

Thus, the magnitude would be A = 5 and angle = 180+θ= 180-20 = 160°

You might be interested in

g 2. In a laboratory experiment on standing waves a string 3.0 ft long is attached to the prong of an electrically driven tuning

abruzzese [7]

Answer:

The tension in string will be "3.62 N".

Explanation:

The given values are:

Length of string:

l = 3 ft

or,

= 0.9144 m

frequency,

f = 60 Hz

Weight,

= 0.096 lb

or,

= 0.0435 kgm/s²

Now,

The mass will be:

= $\frac{0.0435}{9.8}$

= $0.0044 \ kg$

As we know,

⇒ $\lambda=\frac{2L}{n}$

On substituting the values, we get

⇒ $=\frac{2\times 0.9144}{4}$

⇒ $=0.4572 \ m$

or,

⇒ $v=f \lambda$

⇒ $=0.4572\times 60$

⇒ $=27.432 \ m/s$

Now,

⇒ $v=\sqrt{\frac{T}{\mu} }$

or,

⇒ $T=\frac{m}{l}\times v^2$

On putting the above given values, we get

⇒ $=\frac{0.0044}{0.9144}\times (27.432)^2$

⇒ $=\frac{752.51\times 0.0044}{0.9144}$

⇒ $=3.62 \ N$

7 0

3 years ago

Describe the movement of heat energy by the process of convection

atroni [7]

Answer:

Transfer of molecules due to density-difference resulting from increased temperature of the layers of fluid bulk leads to convection.

Explanation:

When a mass of fluid is heated form the lower layers then due to the variation of the density of the fluid at different temperature we observe the movement of molecules leading to convection.

When the lowest level of the fluid is heated it gains temperature and the molecular bulk expands on heating and its density becomes low with respect to the bulk fluid around it and hence it flows upwards to the top most layer being lighter in weight and the lowest layer is occupied by the subsequent colder and denser layer.