All categories

2 years ago

Please help me!!

Physics

1 answer:

den301095 [7]2 years ago

6 0

For objects like insulators (plastics), they can get charged by Friction.
For metals, where there are more loosely bound electrons, they can get charged without contact by induction
For metals, they can also be charged by direct contact by Electrostatic Induction.

You might be interested in

A 15.0-Ω resistor and a coil are connected in series with a 6.30-V battery with negligible internal resistance and a closed swit

Aloiza [94]

Answer:

0.04328 H

0.00288 seconds

0.01326 seconds

Explanation:

V = Voltage = 6.3 V

R = Resistance = 15 Ω

L = Inductance

I = Decayed current = 0.21 A

t = Time to decay = 2 ms

Maximum Current is given by

$I_0=\frac{V}{R}\\\Rightarrow I_0=\frac{6.3}{15}\\\Rightarrow I_0=0.42\ A$

Current in the circuit is given by

$I=I_0exp\frac{-Rt}{L}\\\Rightarrow ln\frac{I_0}{I}=\frac{Rt}{L}\\\Rightarrow L=\frac{Rt}{ln\frac{I_0}{I}}\\\Rightarrow L=\frac{15\times 2\times 10^{-3}}{ln\frac{0.42}{0.21}}\\\Rightarrow L=0.04328\ H$

The inductance is 0.04328 H

Time constant is given by

$\tau=\frac{L}{R}\\\Rightarrow \tau=\frac{0.04328}{15}\\\Rightarrow \tau=0.00288\ s$

Time constant is 0.00288 seconds

Time required is given by

$t=\tau ln\frac{I_0}{I}\\\Rightarrow t=0.00288\times ln\frac{I_0}{0.01I_0}\\\Rightarrow t=0.01326\ s$

The time to reach 1% of its original value is 0.01326 seconds

7 0

4 years ago

Ignoring air resistance, an object in free fall will fall d feet in t seconds, where d and t are related by the algebraic mode

Lostsunrise [7]

Explanation:

Given that,

An object in free fall will fall d feet in t seconds, where d and t are related by the algebraic model as :

$d=16t^2$ ..........(1)

(a) We need to find the time taken by the object to fall 1148 ft. Put this in equation (1) as :

$16t^2=1148$

$t=\sqrt{71.75}$

t = 8.47 seconds

(b) If the object is in free fall for 18.5 sec after it is dropped, then the height of the object is given by :

$d=16(18.5)^2$

d = 5476 ft

Hence, this is the required solution.

7 0

4 years ago

Highlight each sentence that is true about atoms, matter, and electric charge.

lisov135 [29]

Answers B and D are true.

7 0

3 years ago

A student that jumps a vertical height of 50 cm during the hang time activity.

muminat

The hang time of the student is 0.64 seconds, and he must leave the ground with a speed of 3.13 m/s

Why?

To solve the problem, we must consider the vertical height reached by the student as max height.

We can use the following equations to solve the problem:

Initial speed calculations:

$v_{f}^{2}=v_{o}^{2}+2*a*d$

At max height, the speed tends to zero.

So, calculating, we have:

 $v_{f}^{2}=v_{o}^{2}+2*a*d\\\\0=v_{o}^{2}+2*(-9.81\frac{m}{s^{2}})*0.5m\\\\v_{o}^{2}=9.81\frac{m^{2} }{s^{2}}\\\\v_{o}=\sqrt{9.81\frac{m^{2} }{s^{2}}}=3.13\frac{m}{s}$ 

Hang time calculations:

We must remember that the total hang time is equal to the time going up plus the time going down, and both of them are equal,so, calculating the time going down, we have have:

$y-yo=vo.t+\frac{1}{2}*9.81\frac{m}{s^{2}}*t^{2} \\\\0.5m-0=0*t+4.95*t^{2}\\\\t^{2}=\frac{0.5}{4.95}\\\\t=\sqrt{0.101}=0.318s$

Then, for the total hang time, we have:

$TotalHangTime=2*0.318seconds=0.64seconds$

Have a nice day!

3 0

4 years ago

A passenger train left station A at 6:00 p.m. Moving with the average speed 45 mph, it arrived at station B at 10:00 p.m. A tran

marishachu [46]

<h2>Average speed of transit train is 60 mph</h2>

Explanation:

Average speed of passenger train = 45 mph

Time taken from station A to station B for passenger train = 10:00 - 6:00 = 4 hours

Distance between station A to station B = 45 x 4 = 180 miles.

Time taken from station A to station B for transit train = 4 - 1 = 3 hours

Distance between station A to station B = Average speed of transit train x Time taken from station A to station B for transit train

180 = Average speed of transit train x 3

Average speed of transit train = 60 mph

Average speed of transit train is 60 mph

8 0

4 years ago