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2 years ago

4) A motorcycle travels at a constant 90 km per hour in the positive direction down a straight line highway.

Physics

1 answer:

ipn [44]2 years ago

6 0

Answer:

1875 meters

Explanation:

We are given;

Velocity of the motorcycle as 90 km/hr
Time as 75 seconds

We are required to calculate the displacement;

First we will convert speed to m/s
The suitable conversion factor will be;

1 m/s = 3.6 km/hr

Therefore, 90 km/hr

= 90 km/hr ÷ 3.6 km/hr per m/s

= 25 m/s

But;

Displacement = Velocity × time

Thus;

Displacement = 25 m/s × 75 seconds

= 1875 meters

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8. At what position does the mass have the greatest acceleration?

gulaghasi [49]

Answer:

Option (e)

Explanation:

If a mass attached to a spring is stretched and released, it follows a simple harmonic motion.

In simple harmonic motion, velocity of the mass will be maximum, kinetic energy is maximum and acceleration is 0 at equilibrium position (at 0 position).

At position +A, mass will have the minimum kinetic energy, zero velocity and maximum acceleration.

Therefore, Option (e) will be the answer.

6 0

2 years ago

xConsider the following reduction potentials: Cu2+ + 2e– Cu E° = 0.339 V Pb2+ + 2e– Pb E° = –0.130 V For a galvanic cell employi

slega [8]

Answer:

Approximately $\rm 90\; kJ$ .

Explanation:

Cathode is where reduction takes place and anode is where oxidation takes place. The potential of a electrochemical reaction ( $E^{\circ}(\text{cell})$ ) is equal to

$E^{\circ}(\text{cell}) = E^{\circ}(\text{cathode}) - E^{\circ}(\text{anode})$ .

There are two half-reactions in this question. $\rm Cu^{2+} + 2\,e^{-} \rightleftharpoons Cu$ and $\rm Pb^{2+} + 2\,e^{-} \rightleftharpoons Pb$ . Either could be the cathode (while the other acts as the anode.) However, for the reaction to be spontaneous, the value of $E^{\circ}(\text{cell})$ should be positive.

In this case, $E^{\circ}(\text{cell})$ is positive only if $\rm Cu^{2+} + 2\,e^{-} \rightleftharpoons Cu$ is the reaction takes place at the cathode. The net reaction would be

$\rm Cu^{2+} + Pb \to Cu + Pb^{2+}$ .

Its cell potential would be equal to $0.339 - (-0.130) = \rm 0.469\; V$ .

The maximum amount of electrical energy possible (under standard conditions) is equal to the free energy of this reaction:

$\Delta G^{\circ} = n \cdot F \cdot E^{\circ} (\text{cell})$ ,

where

$n$ is the number moles of electrons transferred for each mole of the reaction. In this case the value of $n$ is $2$ as in the half-reactions.
$F$ is Faraday's Constant (approximately $96485.33212\; \rm C \cdot mol^{-1}$ .)

$\begin{aligned}\Delta G^{\circ} &= n \cdot F \cdot E^{\circ} (\text{cell})\cr &= 2\times 96485.33212 \times (0.339 - (-0.130)) \cr &\approx 9.0 \times 10^{4} \; \rm J \cr &= 90\; \rm kJ\end{aligned}$ .

5 0

2 years ago

A wave has a wavelength of 5 meters and a frequency of 3 hertz. What is the speed of the wave?

otez555 [7]

A sound wave in a steel rail has a frequency of 620 Hz and a wavelength of 10.5 ... Find the speed of a wave with a wavelength of 5 m and a frequency of 68 Hz.

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2 years ago

¿Cuál es el parámetro que indica la cantidad de energía liberada en un movimiento sísmico?

artcher [175]

Answer:

Explanation:

en un movimiento sísmico?

3 0

2 years ago

You fire a paintball from a paintball gun straight up into the air at 25.0 m/s. What is the ball velocity at the higher point th

iVinArrow [24]

Given :

You fire a paintball from a paintball gun straight up into the air at 25.0 m/s.

To Find :

What is the ball velocity at the higher point that the ball reaches.

Solution :

We know, when ball is moving upward acceleration due to gravity is applied downward.

So, the ball will decelerate and when ball reaches maximum height its velocity will become zero.

Therefore, ball velocity is 0 m/s at maximum height.

Hence, this is the required solution.

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2 years ago