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Eva8 [605]
3 years ago
13

Also need help with 20 & 21 please

Physics
2 answers:
SSSSS [86.1K]3 years ago
5 0
Number 20 is B and 21 is C
Hoochie [10]3 years ago
5 0
A density is a physical change
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During a single-replacement reaction, a more-active metal will replace a less-active metal in a compound. Which single-replaceme
son4ous [18]

Answer:

Mg will replace Ag in a compound

Explanation:

A single replacement reaction is driven by the position of ions on the activity series.

As a rule of thumb, the position of metal ions on the activity series determines their reactivity.

Metal ions that are above another are more reactive and they will displace those that are lower.

Generally, activity increases as we go up the group.

Mg ions are higher than Ag ions on the series so, Mg will displace Ag from a solution.

8 0
3 years ago
What is the potential energy of a 2 kg ball 15 m in the air?
oee [108]

Answer:

<h2>300 J</h2>

Explanation:

The potential energy of a body can be found by using the formula

PE = mgh

where

m is the mass

h is the height

g is the acceleration due to gravity which is 10 m/s²

From the question we have

PE = 2 × 10 × 15

We have the final answer as

<h3>300 J</h3>

Hope this helps you

7 0
3 years ago
The length of a simple pendulum is 0.760 m, the pendulum bob has a mass of 365 grams, and it is released at an angle of 12.0o to
Allushta [10]

Answer:

0.572 Hz

Explanation:

given,

length of simple pendulum, l = 0.76 m

mass of the bob, m = 365 g = 0.365 Kg

angle made from the vertical, = 12°

frequency, f = ?

f = \dfrac{1}{2\pi}\sqrt{\dfrac{g}{L}}

f = \dfrac{1}{2\pi}\sqrt{\dfrac{9.8}{0.76}}

f = \dfrac{1}{2\pi}\times 3.59

       f = 0.572 Hz

The frequency at which pendulum vibrates is equal to 0.572 Hz

3 0
4 years ago
Help me guys<br><br>Class IX​
goldfiish [28.3K]

Answer:

with right hand grip rule

3. A- south

B- north

C- north

D- south

E- south

F- north

sorry idk what 1st & 2nd question means

4 0
3 years ago
What average force is needed to accelerate a 9.20-gram pellet from rest to 125 m/s over a distance of 0.800 m along the barrel o
aleksklad [387]
Given:
u = 0, initial velocity
v = 125 m/s, final velocity
s = 0.0800 m, distance traveled
9.20 g, the mass of the pellet

If the acceleration is a, then
0² + 2*(a m/s²)*(0.800 m) = (125 m/s)²
1.6a = 15625
a = 9765.625 m/s²

Calculate the force.
F = (9.20 x 10⁻³ kg)*(9765.625 m/s²) = 98.84 N

Answer: 98.8 N (nearest tenth)
8 0
3 years ago
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