Can somebody help me with this quiz please

A thin block of soft wood with a mass of 0.072 kg rests on a horizontal frictionless surface. A bullet with a mass of 4.67 g is

Olegator [25]

Answer:

366.90149 m/s

923.821735 J

324.734 J

Initial Kinetic energy > Final kinetic energy

Explanation:

$m_1$ = Mass of block = 0.072 kg

$m_2$ = Mass of bullet = 4.67 g

$u_1$ = Initial Velocity of block = 0

$u_2$ = Initial Velocity of bullet = 629 m/s

$v_1$ = Final Velocity of block = 17 m/s

$v_2$ = Final Velocity of bullet

In this system the linear momentum is conserved

$m_{1}u_{1}+m_{2}u_{2}=m_{1}v_{1}+m_{2}v_{2}\\\Rightarrow v_2=\frac{m_{1}u_{1}+m_{2}u_{2}-m_1v_1}{m_2}\\\Rightarrow v_2=\frac{0.072\times 0+4.67\times 10^{-3}\times 629-0.072\times 17}{4.67\times 10^{-3}}\\\Rightarrow v_2=366.90149\ m/s$

Final Velocity of bullet is 366.90149 m/s

The initial kinetic energy

$K_i=\frac{1}{2}m_2u_2^2\\\Rightarrow K_i=\frac{1}{2}4.67\times 10^{-3}\times 629^2\\\Rightarrow K_i=923.821735\ J$

The final kinetic energy

$K_f=\frac{1}{2}m_2v_2^2+\frac{1}{2}m_1v_1^2\\\Rightarrow K_f=\frac{1}{2}4.67\times 10^{-3}\times 366.90149^2+\frac{1}{2}0.072\times 17^2\\\Rightarrow K_f=324.734\ J$

Initial Kinetic energy > Final kinetic energy

3 0

3 years ago

A crate resting on a rough horizontal floor is to be moved horizontally. The coefficient of static friction is 0.36. To start th

luda_lava [24]

Answer:

Explanation:

The direction of force will be in upward direction making an angle of θ with the vertical .

Reaction force R = mg - F cosθ

Friction force = μR

= .36 (mg - F cosθ )

Horizontal component of applied force

= F sinθ

For equilibrium

F sinθ = .36 (mg - F cosθ)

F sinθ + .36 F cosθ =.36 mg

F (sinθ + .36 cosθ) = .36 mg

F R( cosδsinθ +sinδ cosθ) = .36 mg ( Rcosδ = 1 . Rsinδ= .36 )

F R sin( θ+δ ) = . 36 mg

F = .36 mg / Rsin( θ+δ )

For minimum F , sin( θ+δ ) should be maximum

sin( θ+ δ ) = sin 90

θ+ δ = 90

Rsinδ / Rcosδ = .36

δ = 20⁰

θ = 70⁰ Ans

5 0

3 years ago

kenneth warmed up a 100- ml sample of air in and expandable container. he displayed the resluts in the following graph. the resl

shepuryov [24]

Answer:

300k

Explanation:

3 0

2 years ago

Use complete sentences to explain how global wind patterns such as the polar easterlies in the southern hemisphere would be impa

Veseljchak [2.6K]

The impact would be great it would possibly freeze the work or melt the polar ice caps and flood the world to were we would invent technology light years away.

7 0

3 years ago

Read 2 more answers

In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 36.0mi/gal , how many liters of gasoline would

Zigmanuir [339]

$36 \frac{mi}{gal} * \frac{1 km}{0.6214 mi}* \frac{1 gal}{3.78 L} = 15.3 \frac{km}{L}

142/15.3=9.27L$

3 0

2 years ago