Answer:
Mass = 18.0 kg
Explanation:
From Hooke's law,
F = ke
where: F is the force, k is the spring constant and e is the extension.
But, F = mg
So that,
mg = ke
On the Earth, let the gravitational force be 10 m/
.
3.0 x 10 = k x 5.0
30 = 5k
⇒ k =
................ 1
On the Moon, the gravitational force is
of that on the Earth.
m x
= k x 5.0
= 5k
⇒ k =
............. 2
Equating 1 and 2, we have;
= 
m = 
= 18.0
m = 18.0 kg
The mass required to produce the same extension on the Moon is 18 kg.
The formula for potential energy is
E(p) = mgh
(Mass x gravity x height)
Therefore energy = (5.3)(9.8)(6.6)
= 342.8 J
How did I get 9.8?
9.8 is the constant for gravity
Answer:
1.01 × 10⁵ Pa
Explanation:
At the surface, atmospheric pressure is 1.013 × 10⁵ Pa.
We need to find the total pressure on the air in the lungs of a person to a depth of 1 meter.
Pressure at a depth is given by :

Where
is the density of air, 
So,

Total pressure, P = Atmospheric pressure + 12 Pa
= 1.013 × 10⁵ Pa + 12 Pa
= 1.01 × 10⁵ Pa
Hence, the total pressure is 1.01 × 10⁵ Pa.
Answer: The speed will be 30 m/s .
Explanation:
Given: Initial velocity of the car: u = 0 m/s
Constant Acceleration: a = 5 m/s²
Time: t= 6 seconds
To find: Final velocity(v)
Formula: v = u+at
Substitute values in the formula, we get
v= 0+(5)(6) m/s
⇒ v= 30 m/s
i.e. Final velocity = 30 m/s
Hence, the speed will be 30 m/s .