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4 years ago

Choose whether each of the following statements is true or false

Physics

1 answer:

kow [346]4 years ago

6 0

Answer:

1. The statement is false.

2. The statement is false.

Explanation:

1. When a ball is thrown vertically up, the air drag is acting downwards which reduces the time the ball spends traveling upwards, but the air drag is acting upwards while the ball is falling, which increases the time the ball spends traveling downwards.

Thus, the statement is false.

2. The potential energy of a particle is given by

$V = mgh$

where, $m$ is the mass of the object, $g$ is the acceleration due to gravity and $h$ is the vertical height traveled by the object.

It does not depend on th initial velocity of the object.

Thus, the statement is false.

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True or false. The number of images formed depends upon the angle between the mirrors.<br>* ****

aleksandrvk [35]

yes it's true................

#indian

3 0

3 years ago

The circuit in Fig. P4.23 utilizes three identical diodes having IS = 10−14 A. Find the value of the current I required to obtai

Sliva [168]

Answer:

$v = \frac{2 V}{3}= 0.667 v$

Since we have identical diodes we can use the equation:

$I_D =I= I_S e^{\frac{V_D}{V_T}}$

And replacing we have: $I = 10^{-14} A e^{\frac{0.667}{0.025}}= 3.86x10^{-3} A = 3.86 mA$

Since we know that 1 mA is drawn away from the output then the real value for I would be

$I_D = I = 3.86 mA -1 mA= 2.86 mA$

And for this case the value for $v_D$ would be:

$V_D = V_T ln (\frac{I_D}{I_T})= 0.025 ln (\frac{0.0029}{10^{-14}})= 0.660 V$

And the output votage on this case would be:

$V = 3 V_D = 3 *0.660 V = 1.98 V$

And the net change in the output voltage would be:

$\Delta V = |2 v-1.98 V| = |0.02 V |= 20 m V$

Explanation:

For this case we have the figure attached illustrating the problem

We know that the equation for the current in a diode id given by:

$I_D = I_s [e^{\frac{V_D}{V_T}} -1] \approx I_S e^{\frac{V_D}{V_T}}$

For this case the voltage across the 3 diode in series needs to be 2 V, and we can find the voltage on each diode $v_1 + v_2 + v_3= 2$ and each voltage is the same v for each diode, so then:

$v = \frac{2 V}{3}= 0.667 v$

Since we have identical diodes we can use the equation:

$I_D =I= I_S e^{\frac{V_D}{V_T}}$

And replacing we have:

$I = 10^{-14} A e^{\frac{0.667}{0.025}}= 3.86x10^{-3} A = 3.86 mA$

Since we know that 1 mA is drawn away from the output then the real value for I would be

$I_D = I = 3.86 mA -1 mA= 2.86 mA$

And for this case the value for $v_D$ would be:

$V_D = V_T ln (\frac{I_D}{I_T})= 0.025 ln (\frac{0.0029}{10^{-14}})= 0.660 V$

And the output votage on this case would be:

$V = 3 V_D = 3 *0.660 V = 1.98 V$

And the net change in the output voltage would be:

$\Delta V = |2 v-1.98 V| = |0.02 V |= 20 m V$

5 0

3 years ago

Determine the power of 60 joules of work done in four seconds

zheka24 [161]

Power = (energy) / (time)

= (60 joules) / (4 seconds)

= 15 joules/second

= 15 watts

7 0

4 years ago

Problem 3: A basketball player is running at 4.75 m/s toward the basket when he jumps into the air to dunk the ball. He maintain

LekaFEV [45]

Answer

given,

speed of the basketball player, v_x = 4.75 m/s

height of the jump = ?

a) initial vertical velocity = 0 m/s

final vertical velocity = ?

height, h = 0.75 m

using equation of motion

v² = u² + 2 g h

v² = 0² + 2 x 9.8 x 0.75

v² = 14.7

v = 3.83 m/s

b) let horizontal distance= x m

maximum height at time , t s

time taken to reach maximum height

$t = \dfrac{3.83}{9.8}$

t = 0.39 s

horizontal distance

= v_x × t

= 4.75 × 0.39

= 1.85 m

horizontal distance is equal to 1.85 m

8 0

3 years ago

What is the diameter of the earth? Explain how long it will take to measure the entire sun.

andreev551 [17]

Answer:

Distance between earth and sun, around 150 million km, is defined as one Astronomical Unit (AU). The radius of the Sun, Run is around 700,000 km. The orbital speed of Earth is around 30 km/s.

Explanation:

5 0

2 years ago

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