A man lifts a 5 Newton bag of groceries

A 30 ky child running at 7 m/s jumps onto a 10 kg sled which was initially at rest. What will be the

Ede4ka [16]

Hope this helps. If you need clarification just ask me!

7 0

3 years ago

A 24-cm-diameter vertical cylinder is sealed at the top by a frictionless 15 kg piston. The piston is 90 cm above the bottom whe

abruzzese [7]

Answer:

(A) $P_i=3249.41\ Pa$

(B) $V_f=0.3358\ m$

Explanation:

Given:

diameter of the cylinder, $d= 0.24\ m$

mass of piston sealing on the top, $m_p=15\ kg$

initial temperature of the piston, $T_i=315+273= 588\ K$

initial height of piston, $h_i=0.9\ m$

atmospheric pressure on the piston, $p_a=1 atm=101325\ Pa$

(A)

Initial pressure of gas is the pressure balanced by the weight of piston:

$P_i=\frac{m_p.g}{\pi.d^2\div 4}$

$P_i=\frac{15\times 9.8}{\pi\times (0.24^2\div 4)}$

$P_i=3249.41\ Pa$

Which is gauge pressure because it is measured with respect to the atmospheric pressure.

(B)

Given:

Final temperature, $T_f=18+273=291\ K$

Now, volume of air initially in the cylinder:

$V_i=\pi.d.h_i$

$V_i=\pi\times 0.24\times 0.9$

$V_i=0.6786\ m^3$

Using gas law:

$\frac{P_i V_i}{T_i}= \frac{P_f V_f}{T_f}$ ........................................(1)

∵In every condition of equilibrium the gas pressure will be balanced by the weight of the piston so it is an isobaric transition.

∴ $P_i=P_f$

Hence eq. (1) is reduced to:

$\frac{V_i}{T_i}= \frac{V_f}{T_f}$

putting respective values:

$\frac{0.6786}{588}= \frac{V_f}{291}$

$V_f=0.3358\ m$

6 0

4 years ago

A ball is thrown vertically down from the edge of a cliff with a speed of 4 m/s, how high is the cliff, if it took 12 s for the

Vesna [10]

Answer:

The height of the cliff from which the ball was dropped from is 224.4m.

\overline{v}={\frac{\Delta x}{\Delta t}}

Given the data in the question;

Initial velocity of the ball;

Time taken by the ball to reach the ground;

Distance or Height of the cliff from which the ball was thrown from;

To get the height of the Cliff, we use the Second Equation of Motion:

Where s is the distance or height, is the initial velocity, t is the time and a is the acceleration. Since the ball was thrown down from a certain height (cliff), its is now under the influence of gravity. acceleration due to gravity;

Hence, the equation becomes

We substitute the given values into the equation

Therefore, the height of the cliff from which the ball was dropped from is 224.4m

Explanation:

3 0

3 years ago

Read 2 more answers

Using what you know about acids, bases and pH. Predict what will happen when vinegar is mixed with water. How would mixing bakin

IRINA_888 [86]

Use the pH scale. When vinegar is mixed with water, the pH is 2.4 to 2.6. Baking soda and water has a pH of 9 to 11. this is because baking soda makes water alkaline.

8 0

3 years ago

Your mother is sure that you were driving too fast because she knows (2 points)

Finger [1]

The answer is either answer B or answer C! Hope that helps

3 0

3 years ago