Question

14. A body is projected with initial velocityof (3i+4j) m/s.
Find its 1) angle of projection
2) maximum height 3) range.(g= 10 m/s-)

15. Derive equation for effective resistance in parallel grouping of resistances.
A wire of resistance 10 ohm is connected to cell of emf 3 volt intemal resistance 2 ohm.
Find current through the wire.

16. Derive equation for magnetic field due to a bar magnet at an arbitrary point.

17. Three particles of masses 1 Kg, 2 Kg, and 3 Kg are placed at the corners of an equivalent
triangle of side 1 m, such that 1 Kg at origin and 2 Kg on X-axis. Locate it's centre of mass.

18. State parallelogram law of vector addition. Derive equation for the magnitude of the resultant
vector.

19. Derive equation for time period of a conical pendulum.​

....pls ans fast

Answer 1

Answer:

master answer is this for me

Answer 2

Given: Initial velocity, u = $(3i+4j) m/s$

Acceleration due to gravity, $g = 9.8 m/s^{2}$

Find:

1) Angle of Projection

2) Maximum Height

3) Range

Solution: Here we have to calculate the angle of projection, maximum height and the range,

The speed of projectile,

$v = |u| = \sqrt{3^{2} +4^{2} } \\\\v = \sqrt{9+16} \\\\v = \sqrt{25}\\\\v = 5 m/s$

We have to calculate the angle of projectile,

$sin\theta = \dfrac{4}{5} , cos\theta = \dfrac{3}{5}$

so, the angle of projection,

$tan\theta = \dfrac{sin\theta}{cos\theta} = \dfrac{4}{5}\times\dfrac{5}{3} \\\\tan\theta = \dfrac{4}{3}$

So, the angle of projection is  $\dfrac{4}{3}$

Now, we have to calculate the maximum height,

We have the expression for the maximum height,

$H = \dfrac{u^{2}(sin\theta)^{2} }{2g} \\\\H = \dfrac{25^{2}\times (\dfrac{4}{5})^{2} }{2\times9.8} \\\\H = \dfrac{400}{19.6} \\\\H = 20.4081m$

So, the maximum height is 20.4081m

Now, we have to calculate the range,

We have the expression for the range,

$R = \dfrac{u^{2}sin2\theta }{g} \\\\R = \dfrac{u^{2}2sin\theta cos\theta }{g} \\\\R = \dfrac{5^{2}\times2\times\dfrac{4}{5} \times\dfrac{3}{5} }{9.8} \\\\R = \dfrac{24}{9.8}\\\\R = 2.4489m$

So, the range is 2.4489m