Physics help please

how do i.... Find the angle between each pair of vectors below. (1 point each) a. a = 2x + 3y a = 4x + 2y

Shalnov [3]

Recall that the dot product between two vectors $\mathbf a$ and $\mathbf b$ satisfies

$\mathbf a\cdot\mathbf b=\|\mathbf a\|\|\mathbf b\|\cos\theta$

where $\|\mathbf x\|$ denotes the norm of a vector $\mathbf x$ , and $\theta$ is the angle between the two vectors.

So if $\mathbf a=(2,3)$ and $\mathbf b=(4,2)$ , then

$(2,3)\cdot(4,2)=\|(2,3)\|\|(4,2)\|\cos\theta$

$\implies2\cdot4+3\cdot2=\sqrt{2^2+3^2}\sqrt{4^2+2^2}\cos\theta$

$\implies\cos\theta=\dfrac{14}{\sqrt{13}\sqrt{20}}$

$\implies\theta\approx29.7^\circ$

6 0

3 years ago

Two fish swimming in a river have the following equations of motion:

IRINA_888 [86]

Answer:

The second fish, X2, is moving faster than the first fish, X1

Explanation:

The given parameters for the equation of motion of the fishes are;

X1 = -6.4 m + (-1.2 m/s)×t

X2 = 1.3 m + (-2.7 m/s)×t

The given equation are straight line equations in the slope and intercept form, where the slope is the speed and in m/s and the intercept is the starting point of swimming of the fishes

For the first fish, the intercept = -6.4 m, the slope = the speed = -1.2 m/s

For the second fish, the intercept = 1.3 m, the slope = the speed = -2.7 m/s

Whereby the fishes are swimming in the opposite direction of the measurement of length, we have;

The magnitude of the speed of the second fish $\left | -2.7 \ m/s \right | = 2.7 \ m/s$ , is larger than the magnitude of the speed of the first fish $\left | -1.2 \ m/s \right | = 1.2 \ m/s$

Therefore, the second fish, X2, is moving faster than the first fish, X1.

8 0

3 years ago

A uniform magnetic field B=5.210 T is perpendicular to the plane of the paper (into the page). The current-carrying wire of valu

ehidna [41]

Answer:5.21 N

Explanation:

Given

B=5.210 T

I=2 A

L=0.5 m

Given Wire is perpendicular to Magnetic field

$\theta =90^{\circ}$

$F=IL\times B$

$F=BIL sin\theta$

$F=5.210\cdot 2\cdot 0.5 sin(90)$

F=5.210 N

as 1 Tesla =1 N/A/m

4 0

3 years ago

In electron capture, which particle would be the beta particle?

Marysya12 [62]

Beta particles ARE electrons.

Also, in one of the great coincidences of Physics, electrons ARE beta particles.

5 0

4 years ago

Hugs 5 things your dog might do when hugged

Nezavi [6.7K]

1. growl: most certainly the dog is going to start growling, but not in a negative, aggressive way, but rather in a surprised, amused way
2. li.ck: the dog will definitely li.ck you, as this is what dogs do when approached
3. pant: dogs pant all the time, especially if it's hot outside, so hugging them makes no difference
4. play: they will want to play with you once they see you love them and want to be around them
5. try to run: some dogs aren't really into hugging, which is why they will try to run away from you because they are confused

4 0

3 years ago