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3 years ago

What average force is required to stop a 980 kg car in 9.0 s if the car is traveling at 91 km/h ?

1 answer:

5 0

Newton's second law of motion:
F=ma
$a = \frac{v}{t}$
You convert from km/h to m/s by dividing by 3.6:
$v = 91 \div 3.6$
$v = 25.3 \: \frac{m}{s}$
Then a is:
$a = \frac{25.3}{9}$
$a = 2.8 \frac{m}{s {}^{2} }$
Then:
F=(980)(2.8)=2744 N

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andrew11 [14]

There are 10⁹ picoseconds in 1 Ms

1 picosecond= 10¹² s

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Thus there are 10⁹ picoseconds in 1 Ms

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3 years ago

A car is travelling with a velocity of 10 m/s and has a mass of 550 kg. The<br> car has<br> energy.

Elenna [48]

Answer: The car has a kinetic energy (because it's in motion) of: $27500J$

Explanation:

$Formula: E=\frac{1}{2}mv^2$

$E=\frac{1}{2}mv^2$

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$E=\frac{1}{2}(55000J)\\E=27500J$

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3 years ago

Use the drop-down menus to complete the statement.

VashaNatasha [74]

Answer: A is your answer i am sorry if i am wrong

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3 years ago

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A rope of negligible mass passes over a uniform cylindrical pulley of 1.50kg massand 0.090m radius. The bearings of the pulley h

boyakko [2]

Answer:

Explanation:

mass of pulley, m3 = 1.5 kg

Radius of pulley, R = 0.09 m

mass of monkey, m2 = 4.5 kg

mass of banana bunch, m1 = 3 kg

Let a is teh acceleration ans T1 and T2 be the tension in the rope.

The moment of inertia of the pulley

I = 0.5 x m3 x R² = 0.5 x 1.5 x 0.09 x 0.09 = 0.006075 kgm²

According to Newton's second law

T1 - m1 g = m1 x a .... (1)

m2 g - T2 = m2 x a ..... (2)

(T2 - T1 ) x R = I x α

where, α is the angular acceleration

α = a / R

(T2 - T1)R = 0.5 x m3 x R² x a / R

T2 - T1 = 0.5 x m3 x a ..... (3)

from (1), (2) and (3)

$a = \frac{m_{2}-m_{1}}{m_{1}+m_{2}+\frac{m_{3}}{2}}\times g$

$a = \frac{4.5-3}{3+4.5+0.75}\times 9.8$

a = 1.78 m/s²

from equation (1)

T1 = m1 ( g + a) = 3 ( 9.8 + 1.78) = 34.77 N

from equation (2)

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3 years ago

To be considered a source of water pollution, the source must include a chemical

forsale [732]

To be considered a source of water pollution, the source must include a chemical is false.

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Instead, there is range of elements from plastic scraps to chemical wastes that comes from either the non-point sources or the point sources. There are organic waste materials, heavy metals, volcanic eruptions, Tsunamis, earthquakes, etc. are also responsible to contaminate water and affect the amphibians as well as humans.

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3 years ago

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