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2 years ago

Listed below are four activities. In which activity is friction useful?

Physics

1 answer:

Likurg_2 [28]2 years ago

4 0

Answer:

a. climbing up a cliff

Explanation:

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a carbon atom with 6 proton and 6 neutron in its nucleus is called carbon-12 the carbon atom with 8 neutrons is called what

daser333 [38]

Answer:

carbon-14 must be the answer

4 0

3 years ago

Help please asap due 20 minutes please help me

Finger [1]

Did you turn it in yet?

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3 years ago

You work at a garden store for the summer, and you lift a 14 kg bag of fertilizer with a force of 227 N.

nika2105 [10]

Answer:

(a) Acceleration of the bag will be a=16.214m/sec^2

(B) Weight of the bag will be 137.2 N

Explanation:

We have given mass of the bag m = 14 kg

Force with which bag is lifted = 227 N

(A) According to newtons law we force is equal to F = ma , here m is mass and a is acceleration

So $227=14\times a$

$a=16.214m/sec^2$

(b) Acceleration due to gravity $g=9.8m/sec^2$

We know that weight is given by W = mg , here m is mass and g is acceleration due to gravity

So weight $W=mg=14\times 9.8=137.2N$

So weight of the bag will be 137.2 N

8 0

3 years ago

There is a plate with moment of inertia Ip = 0.0711 kgm2 , rotating around its center of mass with angular speed of 4.53 rad/s.

Anna007 [38]

Answer:

1) their common angular speed = 3.038 rad/s

2) kinetic energy loss = 0.24J

Explanation:

1) This is a case of conservation of angular momentum.

The initial angular momentum must be equal to the final angular momentum

Initial angular momentum = I x w

Where I = moment of inertia, and

w = angular momentum.

Initial angular momentum = 0.0711 x 4.53 = 0.322 kg-m2-rad/s

After addition of ring, moment of inertia becomes,

0.0711 + 0.0353 = 0.106 kg-m2

Therefore, final angular momentum will be

0.106 x Wf

Where Wf = final common angular velocity

Equating the two angular momentum we have

0.322 = 0.106Wf

Wf = 0.322/0.106 = 3.038 rad/s

2) KE = 1/2 x I x w^2

Initial KE = 1/2 x 0.0711 x 4.53^2

= 0.729 J

Final KE = 1/2 x 0.106 x 3.038^2

= 0.489 J

Loss in KE = 0.729 - 0.489 = 0.24 J

5 0

3 years ago

An ultrasound wave vibrates 30,000 times per second. what is the frequency

erica [24]

Frequency is given in units of Hertz (Hz) and is defined as the number of cycles per second. The sound wave has 30,000 cycles per second, so its frequency is 30,000Hz.
This is more conveniently expressed as 30kHz, where the k indicates a multiplier of 1,000.

5 0

3 years ago