Answer the question below and show all work.

Burka [1]

Answer:

JA

Explanation:

s of time, (b) the velocity and acceleration at t = 2.0 s, (c) the time at which the position is a maximum, (d) the time at which the velocity is zero, and (e) the maximum position. Assume all variable and constants are in SI units.

4 0

3 years ago

Two identical small metal spheres with q1 > 0 and |q1| > |q2| attract each other with a force of magnitude 72.1 mN when se

Brrunno [24]

1) $+2.19\mu C$

The electrostatic force between two charges is given by

$F=k\frac{q_1 q_2}{r^2}$ (1)

where

k is the Coulomb's constant

q1, q2 are the two charges

r is the separation between the charges

When the two spheres are brought in contact with each other, the charge equally redistribute among the two spheres, such that each sphere will have a charge of

$\frac{Q}{2}$

where Q is the total charge between the two spheres.

So we can actually rewrite the force as

$F=k\frac{(\frac{Q}{2})^2}{r^2}$

And since we know that

r = 1.41 m (distance between the spheres)

$F= 21.63 mN = 0.02163 N$

(the sign is positive since the charges repel each other)

We can solve the equation for Q:

$Q=2\sqrt{\frac{Fr^2}{k}}=2\sqrt{\frac{(0.02163)(1.41)^2}{8.98755\cdot 10^9}}}=4.37\cdot 10^{-6} C$

So, the final charge on the sphere on the right is

$\frac{Q}{2}=\frac{4.37\cdot 10^{-6} C}{2}=2.19\cdot 10^{-6}C=+2.19\mu C$

2) $q_1 = +6.70 \mu C$

Now we know the total charge initially on the two spheres. Moreover, at the beginning we know that

$F = -72.1 mN = -0.0721 N$ (we put a negative sign since the force is attractive, which means that the charges have opposite signs)

r = 1.41 m is the separation between the charges

And also,

$q_2 = Q-q_1$

So we can rewrite eq.(1) as

$F=k \frac{q_1 (Q-q_1)}{r^2}$

Solving for q1,

$Fr^2=k (q_1 Q-q_1^2})\\kq_1^2 -kQ q_1 +Fr^2 = 0$

Since $Q=4.37\cdot 10^{-6} C$ , we can substituting all numbers into the equation:

$8.98755\cdot 10^9 q_1^2 -3.93\cdot 10^4 q_1 -0.141 = 0$

which gives two solutions:

$q_1 = 6.70\cdot 10^{-6} C\\q_2 = -2.34\cdot 10^{-6} C$

Which correspond to the values of the two charges. Therefore, the initial charge q1 on the first sphere is

$q_1 = +6.70 \mu C$

8 0

3 years ago

A small airplane flies 780 miles with an average speed of 260 miles per hour. 1.5 hours after the plane leaves, a Boeing 747 lea

Lera25 [3.4K]

Answer:

520 miles per hour

Explanation:

Let the speed of the Boeing 747 be x miles per hour.

The small airplane covers distance of 780 miles with speed 260 miles per hour.

Also,

After 1.5 hours the Boeing 747 leave the same place and reaches at same time. Both covered distance of 780 miles.

So,

<u>Time taken by Boeing 747 + 1.5 hours = Time taken by small plane.</u>

Also,

Time = Distance/ speed

So,

780 / x + 1.5 = 780/ 260

Solving for x, we get:

<u>x = 520 miles per hour</u>

6 0

3 years ago

How long can you keep string cheese in the fridge?

allsm [11]

Cheese attributes its sour taste because of its lactic acid content. However, this should not be an indication to whether the cheese is spoiling already. We can tell its expiry date through the manufacturing details of the product. The product should be good to consume before the manufacturing expiry date. Every package must include expiry date in order to inform the consumer about the range of its consumability attributes. In the case where molds are present on the cheese already, cheese on some parts may not be edible already. Molds are due to the oxidation of glucose through the action of specific bacteria.

8 0

4 years ago

What equation can be used to calculate either wavelength, frequency or speed?

lakkis [162]

Answer:

speed = wavelength * frequency

Explanation:

Thenks and mark me brainliest :)

7 0

3 years ago