Answer:
I. Models are always wrong unless they are proved by a theory. TRUE
II. Elements, such as lead, are made of tiny particles that mostly consist of open space. FALSE
III. The air you breathe is an example of a heterogeneous mixture. FALSE
IV. An isotope of silver-108 has 61 neutrons. TRUE
Explanation:
I. All models are wrong because in order for them to be applied to reality, certain aspects that do not fit the theory must be considered.
II. All elements are made by atoms.
III. The air is an example of a homogeneous mixture of different gases. IA homogeneous system is that material system that has the same intensive properties in any part of that system. One way to check it is by viewing it. If the different parts that make it up cannot be distinguished, it will be homogeneous.
IV. Atomic number of Silver is 47. So if its mass number is 108, it has 61 neutrons and 47 protons
Answer:
11.25m
Explanation:
Given parameters:
Initial velocity = 0m/s
Time of running = 3s
Acceleration = 2.5m/s²
Unknown:
Displacement = ?
Solution:
To solve this problem, we apply one of the motion equations.
S = ut + at²
u is the initial velocity
t is the time taken
a is the acceleration
S = (0 x 3) + ( x 2.5 x 3²) = 11.25m
The answer is D. Exerts a gravitational pull on the star it orbits.
Answer:
2.136 N-m
Explanation:
From the question,
Applying,
Toque = FL...................... Equation 1
Where F = Force applied to the the ball, L = Length of the forearm
From newton's second law of motion,
F = m(v-u)/t................. Equation 2
Where m = mass of the ball, v = final velocity of the ball, u = initial velocity of the ball, t = time.
Given: m = 0.140 kg, u = 0 m/s (from rest), v = 24 m/s, t = 0.425 s
Substitute into equation 2
F = 0.140(24-0)/0.425
F = 7.91 N.
Also Given: L = 0.270 m
Substitute into equation 1
Torque = 7.91×0.270
Torque = 2.136 N-m