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2 years ago

A girl is sitting in a sled sliding horizontally along some snow (there is friction present).

Physics

1 answer:

Mariulka [41]2 years ago

5 0

Answer:

159 N

Explanation:

There are two types of force of friction:

- Static friction: this is the force of friction that occurs when the object is at rest

- Kinetic friction: this is the force of friction that occurs when the object is in motion

In this problem, the girl is sitting on the sled, and the sled is sliding: this means that the object is in motion, therefore the force of friction that we have to calculate in this problem is the force of kinetic friction.

The force of kinetic friction acting on an object sliding over a flat surface is given by

$F_f = \mu_k N$

where

$\mu_k$ is the coefficient of kinetic friction

N is the normal force on the object

In this problem:

$\mu_k = 0.25$

N = 636 N

Therefore, the force of kinetic friction is

$F_f=(0.25)(636)=159 N$

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Luda [366]

A truck is moving with less velocity in the direction in which the truck is moving earlier because the truck has more momentum.

<h3 /><h3>In which direction the truck moves?</h3>

A truck is moving with the velocity of 10 m/s in the same direction in which the truck is moving earlier because the truck has more mass so it has more momentum. Due to collision, the velocity of the truck is slow down but can't be stopped because of high momentum in the truck.

So we can conclude that a truck is moving with less velocity in the direction in which the truck is moving earlier because the truck has more momentum.

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1 year ago

A 22 µF capacitor charged to 0.7 kV and a second 115 µF capacitor charged to 5.5 kV are connected to each other, with the positi

vesna_86 [32]

Answer:

0.099C

Explanation:

First, we need to get the common potential voltage using the formula

$V=\frac {C_2V_2-C_1V_1}{C_1+C_2}$

Where V is the common voltage, C and V represent capacitance and charge respectively. Subscripts 1 and 2 to represent the the first and second respectively. Substituting the above with the following given values then

$C_1=22\times 10^{-6} F\\ C_2=115\times 10^{-6} F\\ V_1= 0.7\times 10^{3}\\V_2=5.5\times 10^{3}$

Therefore

$V=\frac {115\times 10^{-6}\times 5.5\times 10^{3}-22\times 10^{6}\times 0.7\times 10^{3}}{22\times 10^{-6}+115\times 10^{-6}}=4504.3795620437$

Charge, Q is given by CV hence for the first capacitor charge will be $Q_1=C_1V$

Here, $Q_1=22\times 10^{-6}\times 4504.3795620437=0.0990963503649C\approx 0.099C$

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3 years ago

What is a tsunami? How is it formed?

IrinaK [193]

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3 years ago

Read 2 more answers

What are the advantages and disadvantages of renewable and non-renewable energy?

bogdanovich [222]

Renewable energy

<u>Advantages :-</u>

1. Easily regenerate

2. Boost economic growth

3. Easily available

4. Support environment

5. Low maintenance cost

<u>Disadvantages :-</u>

1. Weather dependency

2. High installation cost

3. Noise caused by wind energy

4. Fluctuation problem (solar)

5. Intermittency issue (wind)

Non-renewable energy

<u>Advantages :-</u>

1. Concentrated energy source

2. Reliable energy source

3. Can be built anywhere

4. No radioactive waste

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1. Produces greenhouse gases

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4. Harmful to environment when they are burnt

<em>I hope this helps.....</em>

5 0

3 years ago

0.250 moles of gas are in a piston.The gas does 109 J of work while 240 J of heat are added. What is the change in internal ener

irina [24]

Answer:

+131Joules

Explanation:

Energy can be expressed using below expresion.

ΔE = (q + w).........eqn(1)

q will be + be if heat is gained hence, q= 240 J

work "w" will be - ve if work is done by the system, hence w= -109 J

Then substitute into eqn(1)

Change in Internal energy=

= (240 -109 )

= +131J

6 0

3 years ago