Two boxes are connected by a string. The first box has a mass of 4.2 kg and the

Which factor is most important in determining climate?

alisha [4.7K]

Temperature. The other three dont have anything to do with determining climate

8 0

3 years ago

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A ball has a mass of 1.5kg and is thrown straight up with a speed of 60m/s, what is the ball’s momentum:

madam [21]

Answer:

Assumption: the air resistance on this ball is negligible. Take $g = 10\; \rm m \cdot s^{-2}$ .

a. The momentum of the ball would be approximately $60\;\rm kg \cdot m \cdot s^{-1}$ two seconds after it is tossed into the air.

b. The momentum of the ball would be approximately $\rm \left(-45\; \rm kg \cdot m \cdot s^{-1}\right)$ three seconds after it reaches the highest point (assuming that it didn't hit the ground.) This momentum is smaller than zero because it points downwards.

Explanation:

The momentum $p$ of an object is equal its mass $m$ times its velocity $v$ . That is: $\vec{p} = m \cdot \vec{v}$ .

Assume that the air resistance on this ball is negligible. If that's the case, then the ball would accelerate downwards towards the ground at a constant $g \approx -10\; \rm m \cdot s^{-2}$ . In other words, its velocity would become approximately $10\; \rm m \cdot s^{-1}$ more negative every second.

The initial velocity of the ball is $60\; \rm m \cdot s^{-1}$ . After two seconds, its velocity would have become $60\;\rm m \cdot s^{-1} + 2\; \rm s \times \left(-10\;\rm m \cdot s^{-1}\right) = 40\; \rm m \cdot s^{-1}$ . The momentum of the ball at that time would be around $p = m \cdot v \approx 60\; \rm kg \cdot m \cdot s^{-1}$ .

When the ball is at the highest point of its trajectory, the velocity of the ball would be zero. However, the ball would continue to accelerate downwards towards the ground at a constant $g \approx -10\; \rm m \cdot s^{-2}$ . That's how the ball's velocity becomes negative.

After three more seconds, the velocity of the ball would be $0\; \rm m \cdot s^{-1} + 3\; \rm s \times \left(-10\; \rm m \cdot s^{-2}\right) = -30 \; \rm m \cdot s^{-1}$ . Accordingly, the ball's momentum at that moment would be $p = m \cdot v \approx \left(-45\; \rm kg \cdot m \cdot s^{-1}\right)$ .

3 0

3 years ago

A horizontal uniform meter stick supported at the 50-cm mark has a mass of 0.50 kg hanging from it at the 20-cm mark and a 0.30

ElenaW [278]

Answer:

70 cm

Explanation:

0.5 kg at 20 cm

0.3 kg at 60 cm

x = Distance of the third 0.6 kg mass

Meter stick hanging at 50 cm

Torque about the support point is given by (torque is conserved)

$0.5(50-20)=0.3(60-50)+0.6x\\\Rightarrow x=\dfrac{0.5(50-20)-0.3(60-50)}{0.6}\\\Rightarrow x=20\ cm$

The position of the third mass of 0.6 kg is at 20+50 = 70 cm

7 0

3 years ago

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I need help it is due today

siniylev [52]

Answer:

Option 3. The tennis ball began from rest and rolls at a rate of 14.7 m/s safer 1.5 seconds.

Explanation:

To know the the correct answer to the question, it is important that we know the definition of acceleration.

Acceleration can simply be defined as the rate of change of velocity with time. Mathematically, it is expressed as:

a = (v – u) /t

Where

a => acceleration

v => final velocity

u => Initial velocity

t => time

With the above information in mind, let us consider the options given in the question above to know which conform to the difinition of acceleration.

For Option 1,

We were told that the tennis ball has the following:

Distance = 4 m

Time = 1.5 s

This talks about the speed and not the acceleration.

Speed = distance / time

For Option 2,

We were only told about the average speed and nothing else.

For Option 3,

We were told that the tennis ball have the following:

Initial velocity (u) = 0 m/s

Final velocity (v) = 14.7 m/s

Time = 1.5 s

This talks about the acceleration.

a = (v – u) /t

For Option 4,

We were only told that the tennis rolls to the right at an average speed. This talks about the average velocity. We need more information like time to justify the acceleration.

From the above illustrations, option 3 gives the correct answer to the question.

8 0

3 years ago

Consider the circuit shown in the figure below. (Let R1 = 3.00 Ω, R2 = 8.00 Ω, and = 10.0 V.). . (a) Find the voltage across R1.

Goryan [66]

You take the inverse of the total resistances of each branch and add them up. So if you have 5ohm, 7 ohm, and 10ohm, you would add 1/5 + 1/7 + 1/10 = 31/70 Then flip it back by either using the x−1 (inverse) key on your calculator or simply dividing 70 by 31 to get a total of 2.26ohms

8 0

3 years ago