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nordsb [41]
3 years ago
12

7. A car moving at 10m/s (about 22.4 mph) crashes into a barrier and stops in 0.25 m.

Physics
1 answer:
Galina-37 [17]3 years ago
6 0

Answer:

a) 0.05s

b) 4000N

Explanation:

a)When car is stopped its final velocity become zero

U- 10 m/s

V- 0 m/s

S - 0.25 m

t -?

S = (v+u)*t/2

0.25 =(10+0)*t/2

t = 0.05s

b) If we happened to calculate the avarage force we have to consider about acceleration

V= 0

U = 10

t = 0.05 s

a =?

V = U + at

0 = 10 -a * 0.05

a = 200 m/s2

F = m *a

= 20 * 200

= 4000N

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Answer:

10 °C

Explanation:

Applying

q = cm(t₂-t₁)............... Equation 2

Where q = heat energy, c = specific heat of ethanol, m = mass of ethanol, t₁ = initial temperature, t₂ = Final temperature.

Given: c = 2.44 J/g.°C,  m = 300 g, q = 14640 J, t₂ = 30°C

Substitute into equation 2 and solve for t₁

14640 = 2.44×300(30-t₁)

14640 = 732(30-t₁)

732(30-t₁) = 14640

(30-t₁)  = 14640/732

(30-t₁)  = 20

t₁ = 30-20

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Answer:

Explanation:

This problem indicates that the speed of light in a material medium is 0.5 10⁸ m / s, they ask to find the critical angle between the material and the vacuum

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for the angle criticize the angles tea2 = 90

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Answer:

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We are to get the volume rate of flows

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From the attachment I uploaded, we have a formula named equation 1 from which I have plugged in these values

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