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1 year ago

What are some downsides to fossil fuels? (Select all that apply.)

Physics

1 answer:

Evgen [1.6K]1 year ago

6 0

Answer:

They release large amounts of carbon dioxide when burned.

They are expensive to extract compared to other forms of energy.

They do not replenish themselves

Explanation:

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In a closed system, a cart with a mass of 1.5 kg is rolling to the right at 1.4 m/s, while another cart of mass 1.0 kg is rollin

bija089 [108]

Answer: The correct option is (c.).

Explanation:

Mass of the cart A= 1.5 kg

Velocity of Cart A = 1.4 m/s towards right

Mass of the cart B = 1.0 kg

Velocity of Cart B = 1.4 m/s towards left

Momentum (P)= Mass × Velocity

$P_A=1.5 kg\times 1.4 m/s=2.1 kg m/s$

$P_B=1.0 kg\times (-1.4m/s)=-1.4 kg m/s$

(Negative sign means velocity of the cart is in opposite direction of that of the cart A)

Total Momentum = $P_A+P_B=2.10 kg m/s-1.40 kg m/s=0.70 kg m/s$

Hence, the correct option is (c.).

7 0

2 years ago

Read 2 more answers

g A loop circuit has a resistance of R1 and a current of 2 A. The current is reduced to 1.4 A when an additional 2.2 Ω resistor

Mrrafil [7]

Answer:

R1 = 5.13 Ω

Explanation:

From Ohm's law,

V = IR............... Equation 1

Where V = Voltage, I = current, R = resistance.

From the question,

I = 2 A, R = R1

Substitute into equation 1

V = 2R1................ Equation 2

When a resistance of 2.2Ω is added in series with R1,

assuming the voltage source remain constant

R = 2.2+R1, and I = 1.4 A

V = 1.4(2.2+R1)................. Equation 3

Substitute the value of V into equation 3

2R1 = 1.4(2.2+R1)

2R1 = 3.08+1.4R1

2R1-1.4R1 = 3.08

0.6R1 = 3.08

R1 = 3.08/0.6

R1 = 5.13 Ω

6 0

2 years ago

An object rotates about a fixed axis, and the angular position of a reference line on the object is given by θ = 0.220e3t, where

OLga [1]

Answer: $a_{t}=3.96$

$a_{c}=0.8712$

Explanation:

Given

$\theta =0.220e^{3t}$

r=2cm

Now angular velocity is given by $\omega =\frac{\mathrm{d}\theta}{\mathrm{d}t}$

$\omega =0.66e^{3t}$

Now linear velocity(v) is given = $\omega r$

$v=1.32e^{3t}$

Now tangential component of acceleration is given by

$a_{t}=\frac{\mathrm{d}\vec{v}}{\mathrm{d}t}=3.96e^{3t}$

at t=0

$a_{t}=3.96cm/s^2$

radial component of acceleration is given by

$a_{c}=\omega ^{2}r$

$a_{c}=0.4356e^{6t}\times 2$

$a_{c}=0.8712e^{6t} cm/s^{2}$

at t=0

$a_c=0.8712 cm/s^{2}$

5 0

2 years ago

Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he p

lapo4ka [179]

Answer:

He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.

6 0

1 year ago

Which describes the ability to do work or to cause change?

Ierofanga [76]

Answer: Energy

Explanation: The ability to do work or cause change is called energy. Energy comes from many sources, and is found in two main forms. One form, potential energy, is energy that has the potential, in an object at rest, to do work later. An example of this would be a car parked at the top of a hill with its brakes on.

6 0

2 years ago

Read 2 more answers