Answer:
What is a Pure Substance?
Explanation:
It is something which cannot be divided into parts by physical means, as it's all made up of the same thing. Pure substances are either elements or compounds. Elements can NOT be separated into other types of matter (physically or chemically).
Answer:
Acceleration of the crate is 0.362 m/s^2.
Explanation:
Given:
Mass of the box, m = 40 kg
Applied force, F = 15 N
Angle at which the force is applied,
= 15°
We have to find the magnitude of the acceleration.
Let the acceleration be "a".
FBD is attached with where we can see the horizontal and vertical component of force.
⇒
and ⇒ 
⇒
⇒ 
⇒ Applying concept of forces.
⇒
⇒ 
⇒
<em> ...Newtons second law Fnet = ma</em>
⇒
⇒ Plugging the values.
⇒
<em>...f is the friction which is zero here.</em>
⇒ 
⇒ 
Magnitude of the acceleration of the crate is 0.362 m/s^2.
Answer:
She must be launched with minimum speed of <u>57.67 m/s</u> to clear the 520 m gap.
Step-by-step explanation:
Given:
The angle of projection of the projectile is,
°
Range of the projectile is,
m.
Acceleration due to gravity, 
The minimum speed to cross the gap is the initial speed of the projectile and can be determined using the formula for range of projectile.
The range of projectile is given as:

Plug in all the given values and solve for minimum speed,
.

Therefore, she must be launched with minimum speed of 57.67 m/s to clear the 520 m gap.
Answer:
4948020
Explanation:
(6.9*10-6)(770*102)
<u>Multiply 6.9 by 10
.
</u>
(
69
−
6
)
(
770
⋅
102
)
<u>Subtract 6 from 69
.
</u>
63
(
770
⋅
102
)
<u>Multiply 770 by 102
.
</u>
63
⋅
78540
<u>Multiply 63 by 78540
.
</u>
4948020
Answer:

Explanation:
The system can be modelled appropriately by the use of the Principle of Momentum Conservation and Impact Theorem:

The average force exerted on her:
