Answer:
1) D, 2) D, 3) B, 4) B, 5) C
Explanation:
You are asked to select the correct answer
1) The conservation of energy is one of the most important principles of physics that allows solving countless problems in life.
the correct answer is D
2) when a body falls, the gravitational potential energy is transformed into kinetic energy and both are transformed into thermal energy
the correct answer is D
3) When the gravitational potential energy is maximum, the kinetic energy is minimum and when the kinetic energy is maximum, the gravitational energy is minimum.
Correct answer B
4) speed is defined by
v = x / t
so the correct answer is B in the SI system
5) when we repeat a measurement several times, the random or statistical errors decrease, therefore the confidence of the measurement increases.
The correct answer is C
Q. The energy emitted from the sun is a product of ________.
A. Fusion
Answer:
X-rays go all the way through the body, but ultraviolet rays do not.
Explanation:
An x-ray will show inside the body, but uv light isn't strong enough to go all the way through the body.
Answer:
m = 20,000 kg
Explanation:
Force, 
Acceleration of the shark, 
It is required to find the mass of the shark. Let m is the mass. Using second law of motion to find it as follows :
F = ma
Putting the value of F and a to find m
So, the shark's mass is 20,000 kg.
Answer:
1470kgm/s
Explanation:
Given parameters:
Mass of the rock = 50kg
Time taken for the free fall = 3s
Unknown:
Change in momentum = ?
Solution:
The change in momentum will be difference between the ending momentum and finishing momentum.
Momentum is the product of mass and velocity
Momentum = mass x velocity
Initial momentum = 0, the velocity is 0
Final momentum = mass x final velocity
let us find the final velocity;
V = U + gt
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity = 9.8m/s²
t is the time
V = 0 + 9.8x3 = 29.4m/s
So;
Change in momentum = 50 x 29,4 = 1470kgm/s
