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2 years ago

A 2.10 X 10^3 kg car starts from rest at the top of a 5.0

Physics

1 answer:

xeze [42]2 years ago

4 0

Answer:

3.80 m/s

Explanation:

Solution: From the question we have:

A 2.10 x 10^3 kg car starts from rest at the top of a 5.0 m long driveway that is sloped at 20 degrees with the horizontal.

average friction force of 4.0 x 10^3 N impedes the motion

To find out: find the speed of the car at the bottom of the driveway.

=>h = 5×sin20 = 1.71 m.

PE = mgh = 2100×9.8×1.71 = 35,192 J.

KE = PE-work done by frictional force

KE=PE-4000×5

0.5mV^2 = 35192 - 4000×5

1050V^2 = 15,192

V^2 = 14.47

V = 3.80 m/s.

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3 years ago

Find the frequency of a wave with the wavelength 3.5 m and the speed is 50 m/s. <br>

Andru [333]

Answer:

8.57 Hz

Explanation:

From the question given above, the following data were obtained:

Wavelength (λ) = 3.5 m

Velocity (v) = 30 m/s

Frequency (f) =?

The velocity, wavelength and frequency of a wave are related according to the equation:

Velocity = wavelength × frequency

v = λ × f

With the above formula, we can simply obtain the frequency of the wave as follow:

Wavelength (λ) = 3.5 m

Velocity (v) = 30 m/s

Frequency (f) =?

v = λ × f

30 = 3.5 × f

Divide both side by 3.5

f = 30 / 3.5

f = 8.57 Hz

Thus, the frequency of the wave is 8.57 Hz

7 0

2 years ago

What forces act to pull the poles of a magnet together, or to push them apart?

masya89 [10]

Answer:

Gravity,

I hope this correct

4 0

3 years ago

On a cold winter day, a penny (mass 2.50 g) and a nickel (mass 5.00 g) are lying on the smooth (frictionless) surface of a froze

sp2606 [1]

Answer:

0.78333 m/s in the opposite direction

1.566 m/s in the same direction

Explanation:

$m_1$ = Mass of penny = 0.0025 kg

$m_2$ = Mass of nickel = 0.005 kg

$u_1$ = Initial Velocity of penny = 2.35 m/s

$u_2$ = Initial Velocity of nickel = 0 m/s

$v_1$ = Final Velocity of penny

$v_2$ = Final Velocity of nickel

As momentum and Energy is conserved

$m_{1}u_{1}+m_{2}u_{2}=m_{1}v_{1}+m_{2}v_{2}$

${\tfrac {1}{2}}m_{1}u_{1}^{2}+{\tfrac {1}{2}}m_{2}u_{2}^{2}={\tfrac {1}{2}}m_{1}v_{1}^{2}+{\tfrac {1}{2}}m_{2}v_{2}^{2}$

From the two equations we get

$v_{1}=\frac{m_1-m_2}{m_1+m_2}u_{1}+\frac{2m_2}{m_1+m_2}u_2\\\Rightarrow v_1=\frac{0.0025-0.005}{0.0025+0.005}\times 2.35+\frac{2\times 0.5}{0.4005+0.5}\times 0\\\Rightarrow v_1=-0.78333\ m/s$

The final velocity of the penny is 0.78333 m/s in the opposite direction

$v_{2}=\frac{2m_1}{m_1+m_2}u_{1}+\frac{m_2-m_1}{m_1+m_2}u_2\\\Rightarrow v_2=\frac{2\times 0.0025}{0.0025+0.005}\times 2.35+\frac{0.005-0.0025}{0.005+0.0025}\times 0\\\Rightarrow v_2=1.566\ m/s$

The final velocity of the nickel is 1.566 m/s in the same direction

6 0

2 years ago

Need help ASAP please help me please

lbvjy [14]

Answer:

145

Explanation:

5 0

2 years ago