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2 years ago

14

A blue train of mass 50 kg moves at 4 m/s toward a green train of 30 kg initially at rest. The trains collide. After the collisi

on the green train moves with a speed of 3 m/s. What is the final momentum of the green train? A. 90 kgm/s B. 20 kgm/s C. 200 kgm/s D. 110 kgm/s

1 answer:

ra1l [238]2 years ago

7 0

Explanation:

Momentum = mass × speed

p = (30 kg) (3 m/s)

p = 90 kg m/s

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When plugging in metric facts, always remember that 1 big unit = # small units. Fill in these facts: 1.________ s= ________μs 2.

balandron [24]

Answer:

1. 1 s = 1 x 10⁶ μs

2. 1 g = 0.001 kg

3. 1 km = 1000 m

4. 1 mm = 1 x 10⁻³ m

5. 1 mL = 1 x 10⁻³ L

6. 1 g = 100 dg

7. 1 cm = 1 x 10⁻² m

8. 1 ms = 1 x 10⁻³ s

Explanation:

1.

1 x 10⁻⁶ s = 1 μs

(1 x 10⁻⁶ x 10⁶) s = 1 x 10⁶ μs

<u>1 s = 1 x 10⁶ μs</u>

2.

1000 g = 1 kg

1 g = 1/1000 kg

<u>1 g = 0.001 kg</u>

3.

<u>1 km = 1000 m</u>

<u></u>

4.

<u>1 mm = 1 x 10⁻³ m</u>

<u></u>

5.

<u>1 mL = 1 x 10⁻³ L</u>

<u></u>

6.

1 x 10⁻² g = 1 dg

(1 x 10⁻² x 10²) g = 1 x 10² dg

<u>1 g = 100 dg</u>

<u></u>

7.

<u>1 cm = 1 x 10⁻² m</u>

<u></u>

8.

<u>1 ms = 1 x 10⁻³ s</u>

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3 years ago

At a distance of 11 cm from a presumably isotropic, radioactive source, a pair of students measure 65 cps (cps = counts per seco

Alborosie

To solve the problem, it is necessary the concepts related to the definition of area in a sphere, and the proportionality of the counts per second between the two distances.

The area with a certain radius and the number of counts per second is proportional to another with a greater or lesser radius, in other words,

$A_1*m=M*A_2$

$A_i =Area$

M,m = Counts per second

Our radios are given by

$r_1 = 11cm$

$R_2 = 20cm$

$m = 65cps$

Therefore replacing we have that,

$A_1*m=M*A_2$

$4\pi r_1^2*m = M * 4\pi R_2^2 M$

$r^2*m=MR^2$

$M = \frac{m*r^2}{R^2}$

$M = \frac{65*11^2}{20^2}$

$M = 19.6625cps$

Therefore the number of counts expect at a distance of 20 cm is 19.66cps

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3 years ago

A mass of 8 kg moves at a rate of 14.3 m/sec. what is the KE developed by the mass?

Lynna [10]

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I’m guessing it’s the last one, trough

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2 years ago