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3 years ago

8

What is the magnitude of the instantaneous velocity (speed) of a freely falling object 25 s after it is released from a position

of rest? Consider the acceleration of gravity to be 10m/s^2. Answer in unit of m/s

1 answer:

Marta_Voda [28]3 years ago

6 0

Answer:

The instantaneous velocity of the object is 250 m/s

Explanation:

Given;

time of the object motion, t = 25 s

acceleration due to gravity, g = 10 m/s²

The instantaneous velocity of the object is given as;

v = u + gt

where;

u is the initial velocity of the object = 0 (since it was released from rest)

Substitute the givens;

v = 0 + (10 x 25)

v = 250 m/s

Therefore, the instantaneous velocity of the object is 250 m/s

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Quantum physics would most likely be needed to understand the motion of which of the following?

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The correct answer is A.

Quantum physics is the branch of science which deals with the behavior of matter and light on atomic and subatomic level. So, to understand the motion of an atom we would need quantum physics. Motion of a ball and a galaxy can be understood by Newtonian mechanics.

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4 years ago

An expression representing a chemical reaction; the formulas of the reactants are connected by an arrow with the formulas for th

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Explanation:

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For example, chemical reaction between hydrogen and oxygen will result in the formation of water. The reaction equation will be as follows.

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3 years ago

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What change takes place in a wave when the frequency of the wave increases?

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The answer is C. As the frequency of the waves increases, a greater number of wavelengths pass a given point per second. From the wave formula, we see that there is an indirect relationship between frequency and the wavelength. thus, as the frequency increases the wavelength decreases resulting to a smaller distance between the waves which will show greater number of wavelengths between waves.

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3 years ago

A Carnot engine operates between temperature levels of 600 K and 300 K. It drives a Carnot refrigerator, which provides cooling

KATRIN_1 [288]

Explanation:

Formula for maximum efficiency of a Carnot refrigerator is as follows.

$\frac{W}{Q_{H_{1}}} = \frac{T_{H_{1}} - T_{C_{1}}}{T_{H_{1}}}$ ..... (1)

And, formula for maximum efficiency of Carnot refrigerator is as follows.

$\frac{W}{Q_{C_{2}}} = \frac{T_{H_{2}} - T_{C_{2}}}{T_{C_{2}}}$ ...... (2)

Now, equating both equations (1) and (2) as follows.

$Q_{C_{2}} \frac{T_{H_{2}} - T_{C_{2}}}{T_{C_{2}}}$ = $Q_{H_{1}} \frac{T_{H_{1}} - T_{C_{1}}}{T_{H_{1}}}$

$\gamma = \frac{Q_{C_{2}}}{Q_{H_{1}}}$

= $\frac{T_{C_{2}}}{T_{H_{1}}} (\frac{T_{H_{1}} - T_{C_{1}}}{T_{H_{2}} - T_{C_{2}}})$

= $\frac{250}{600} (\frac{(600 - 300)K}{300 K - 250 K})$

= 2.5

Thus, we can conclude that the ratio of heat extracted by the refrigerator ("cooling load") to the heat delivered to the engine ("heating load") is 2.5.

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3 years ago

A charge of 7.00 mC is placed at opposite corners corner of a square 0.100 m on a side and a charge of -7.00 mC is placed at oth

andrew-mc [135]

Answer:

4.03\times10^{7}N[/tex], 135°

Explanation:

charge, q = 7 mC = 0.007 C

charge, - q = - 7 mC = - 0.007 C

d = 0.1 m

Let the force on charge placed at C due to charge placed at D is FD.

$F_{D}=\frac{kq^{2}}{DC^{2}}$

$F_{D}=\frac{9 \times10^{9}\times 0.007 \times 0.007}{0.1^{2}}=4.41 \times 10^{7}N$

The direction of FD is along C to D.

Let the force on charge placed at C due to charge placed at B is FB.

$F_{B}=\frac{kq^{2}}{BC^{2}}$

$F_{B}=\frac{9 \times10^{9}\times 0.007 \times 0.007}{0.1^{2}}=4.41 \times 10^{7}N$

The direction of FB is along C to B.

Let the force on charge placed at C due to charge placed at A is FA.

$F_{A}=\frac{kq^{2}}{AC^{2}}$

$F_{D}=\frac{9 \times10^{9}\times 0.007 \times 0.007}{0.1 \times\sqrt{2} \times 0.1 \times\sqrt{2}}=2.205 \times 10^{7}N$

The direction of FA is along A to C.

The net force along +X axis

$F_{x}=F_{A}Cos45-F_{D}$

$F_{x}=2.205\times10^{7}Cos45-4.41\times10^{7}=-2.85\times10^{7}N$

The net force along +Y axis

$F_{y}=F_{B}-F_{A}Sin45$

$F_{y}=4.41\times10^{7}-2.205\times10^{7}Sin45=2.85\times10^{7}N$

The resultant force is given by

$F=\sqrt{F_{x}^{2}+F_{y}^{2}}=\sqrt{(-2.85\times10^{7})^{2}+(2.85\times10^{7})^{2}}$

$F = 4.03\times10^{7}N$

The angle from x axis is Ф

tan Ф = - 1

Ф = -45°

Angle from + X axis is 180° - 45° = 135°

5 0

3 years ago