Question

$\huge \mathfrak{hello}$
______▪▪▪■□■□■▪▪▪_______


Please solve these numericals.

I need exact right solution because i wanna sure ,,

Please do fast ,ppls..
i need each n every que's sol;,

No silly solutions ,otherwise u'll reported, ...


$<marquee > be brainy$
!!


^_^♥

Answer 1

$hlo$

hope the attachment will help u

Answer 2

Question 1 :

Given info

Initial velocity ( u ) = 40 km/hr

Final velocity ( v ) = 60 km/hr

Mass ( m ) = 2000 kg

Work done = Change in kinetic energy

                   = 1/2 m v² - 1/2 m u²

                   = 1/2 m ( v² - u² )

                   = 1/2 × 2000 kg × ( 60² - 40² )

                   = 1000 kg × ( 60 + 40 )( 60 - 40 )

                   = 1000 kg × 100 × 20 m²/s²

                   = 1000 × 2000 J

                   = 2000 kJ

ANSWER :

The work done would be 2000 kJ

Question 2 :

Given info :

Mass of bullet ( m₁ ) = 20 g

Initial velocity ( u₁ ) = 0

Final velocity ( v₁ ) = 150 m/s

Mass of rifle ( m₂ ) = 2 kg

                              = 2,000 g

Final velocity ( v₂ ) = recoil = ?

Sum of momentums would be equal ...

m₁ u₁ + m₂u₁ = m₂ u₁ + m₂ u₂

==> 20 × 0 + 2000 × 0 = 150 × 20 + 2000 × v

==> 2000 v = - 3000

==> v = -3000 / 2000

==> v = -1.5 m/s

ANSWER :

The recoil would be 1.5 m/s backwards .

Question 3 :

Given info

Speed of wave ( v ) = 440 m/s

Frequency ( f ) = 220 Hz

Speed of wave = frequency × wavelength

==> wavelength = speed of wave / frequency

                           = 440 m/s / 220 Hz

                           = 2 m

ANSWER :

The wavelength of the sound wave is 2 m