The most reactive element is fluorine, the first element in the halogen group. The most reactive metal is francium, the last alkali metal (and most expensive element).

6 0

2 years ago

The magnetic field of a magnet is strongest

Talja [164]

The answer is C !!!!

4 0

3 years ago

Using a scale of 1 cm to represent 10 N, find the size and direction of the resultant of forces of 50 N

marta [7]

Answer:

$74.31\ \text{N}$

$16.59^{\circ}$

Explanation:

P = 50 N

Q = 30 N

$\theta$ = Angle between the vectors = $45^{\circ}$

Resultant is given by

$R=\sqrt{P^2+Q^2+2PQ\cos\theta}\\\Rightarrow R=\sqrt{50^2+30^2+2\times 50\times 30\times \cos45^{\circ}}\\\Rightarrow R=74.31\ \text{N}$

Angle of resultant

$\phi=\tan^{-1}\dfrac{Q\sin\theta}{P+Q\cos\theta}\\\Rightarrow \phi=\tan^{-1}\dfrac{30\times \sin45^{\circ}}{50+30\cos45^{\circ}}\\\Rightarrow \phi=16.59^{\circ}$

Magnitude of the resultant is $74.31\ \text{N}$

Direction of the resultant is $16.59^{\circ}$

4 0

3 years ago