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ladessa [460]
3 years ago
13

You apply a potential of 2.0 volts to an object made of unknown material and observe that a current of 0.80 A flows through the

object. When you apply a current of 4.0 volts, you measure a current of 1.60 A through the object. What can you conclude about the material the object is made of?
Physics
1 answer:
BaLLatris [955]3 years ago
8 0

Answer:

Explanation:

Case 1: V = 2 v , I = 0.8 A

According to the Ohm's law, the current flows through the conductor is directly proportional to the potential difference applied across the conductor.

V = I R

where, R is the resistance of the conductor.

R = 2 / 0.8 = 2.5 ohm

Case 2: V = 4 V, I = 1.60 A

R = 4 / 1.6 = 2.5 ohm

Thus, the resistance of material is 2.5 ohm.

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People travel from all over the world to see more than 30 glaciers at Glacier National Park in Alaska.
Whitepunk [10]
The answer I believe is c
Explanation
During the day when temperatures are higher, the snow melts and water enters the cracks in the rock. When the temperature drops below 0°C the water in the crack freezes and expands by about 9 per cent. This makes the crack larger.
3 0
3 years ago
Read 2 more answers
Asap. I need an explanaton to how this works as well
bazaltina [42]

Answer:

B: Electrical - Heat

C: Electrical - kinetic

Explanation:

When the hair dryer is plugged to electric supply, electrical energy is converted into heat. When this electricity is circulated through a resistor, heat is now created in the form of losses which make the air around the resistors to be heated.

After that process, this electricity turns into kinetic energy because it forms Electric energy which moves the fan in order to create a flow with the air that's heated.

5 0
3 years ago
A 93.5 kg snowboarder starts from rest and goes down a 60 degree slope with a 45.7 m height to a rough horizontal surface that i
frosja888 [35]

Answer:

a. 29.9 m/s, b. 29.6 m/s, c. 44.7 m

Explanation:

This can be answered with either force analysis and kinematics, or work and energy.

a) Using force analysis, we can draw a free body diagram for the snowboarder.  There are two forces: normal force perpendicular to the slope and gravity down.

Sum of the forces parallel to the slope:

∑F = ma

mg sin θ = ma

a = g sin θ

Therefore, the velocity at the bottom is:

v² = v₀² + 2a(x - x₀)

v² = (0)² + 2(9.8 sin 60°) (45.7 / sin 60° - 0)

v = 29.9 m/s

Alternatively, using energy:

PE = KE

mgh = 1/2 mv²

v = √(2gh)

v = √(2×9.8×45.7)

v = 29.9 m/s

b) Drawing a free body diagram, there are three forces on the snowboarder.  Normal force up, gravity down, and friction to the left.

Sum of the forces in the y direction:

∑F = ma

N - mg = 0

N = mg

Sum of the forces in the x direction:

∑F = ma

-F = ma

-Nμ = ma

-mgμ = ma

a = -gμ

Therefore, the snowboarder's final speed is:

v² = v₀² + 2a(x - x₀)

v² = (29.9)² + 2(-9.8×.102) (10 - 0)

v = 29.6 m/s

Using energy instead:

KE = KE + W

1/2 mv² = 1/2 mv² + F d

1/2 mv² = 1/2 mv² + mgμ d

1/2 v² = 1/2 v² + gμ d

1/2 (29.9)² = 1/2 v² + (9.8)(0.102)(10)

v = 29.6 m/s

c) This is the same as part a, but this time, the weight component parallel to the incline is pointing left.

∑F = ma

-mg sin θ = ma

a = -g sin θ

Therefore, the final height reached is:

v² = v₀² + 2a(x - x₀)

(0)² = (29.6)² + 2(-9.8 sin 30°) (h / sin 30° - 0)

h = 44.7 m

Using energy:

KE = PE

1/2 mv² = mgh

h = v² / (2g)

h = (29.6)² / (2×9.8)

h = 44.7 m

3 0
4 years ago
A wheel has a constant angular acceleration of 1.8 rad/s2. During a certain 4.0 s interval, it turns through an angle of 45 rad.
tankabanditka [31]

Answer:

4.25 s

Explanation:

Given:

angular acceleration'α'=  1.8 rad/s²

angle 'θ'= 45 rad

time 't'= 4s

initial angular velocity 'w_{o}'=0rad^{-1}

as we know that,

θ= w_{1}t + \frac{1}{2} \alpha t^{2}

45 = 4 w_{1} + (0.5 x 1.8 x 16)

45- 14.4 = 4 w_{1}

30.6 = 4 w_{1}

w_{1}= 7.65 rad^{-1}

Next is to find t by using the equation

w_{1} =  w_{o} + \alpha t_{1}

7.65= 0 + (1.8)t_{1}

t_{1}= 7.65/1.8

t_{1}= 4.25 s

Therefore, At the start of 4s interval the motion is at 4.25 second

7 0
4 years ago
A particle of mass m= 2.5 kg has velocity of v = 2 i m/s, when it is at the origin (0,0). Determine the z- component of the angu
melomori [17]

Answer:

please read the answer below

Explanation:

The angular momentum is given by

|\vec{L}|=|\vec{r}\ X \ \vec{p}|=m(rvsin\theta)

By taking into account the angles between the vectors r and v in each case we obtain:

a)

v=(2,0)

r=(0,1)

angle = 90°

L=(2.5kg)(1)(2\frac{m}{s})sin90\°=5.0kg\frac{m}{s}

b)

r=(0,-1)

angle = 90°

L=(2.5kg)(1)(2\frac{m}{s})sin90\°=5.0kg\frac{m}{s}

c)

r=(1,0)

angle = 0°

r and v are parallel

L = 0kgm/s

d)

r=(-1,0)

angle = 180°

r and v are parallel

L = 0kgm/s

e)

r=(1,1)

angle = 45°

L = (2.5kg)(2\frac{m}{s})(\sqrt{2})sin45\°=5kg\frac{m}{s}

f)

r=(-1,1)

angle = 45°

the same as e):

L = 5kgm/s

g)

r=(-1,-1)

angle = 135°

L=(2.5kg)(2\frac{m}{s})(\sqrt{2})sin135\°=5kg\frac{m}{s}

h)

r=(1,-1)

angle = 135°

the same as g):

L = 5kgm/s

hope this helps!!

4 0
4 years ago
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