We don't know that at all. The 3rd law says that the REaction is opposite and EQUAL to the action. We don't know where that "twice as much" comes from.
Answer:
D. Validity group
Explanation:
A validity group is not necessarily a component of a normal experiment.
A normal experiment is made up of the dependent variables, independent variables, and most times the control group.
- The dependent variable is one that relies on the outcome of the effect produced from the experimental design
- The independent variable is the one that causes a desired effect under the study.
- The control group is a group that does not receive any treatment nor attenuation of the conditions.
Answer:
0.001152m
Explanation:
Linear expansivity of a material is the change in length of the material per unit length per degree rise in temperature. Mathematically,
¢ = ∆L/L1∆°C
¢ is the linear expansivity of the material = 12 x 10⁻⁶ °C⁻¹
Where ∆L is the change in length = L2-L1
L2 is the final length = ?
L1 is the initial length = 12m
∆°C is the change in temperature = °C2 - °C1 = 50-(-30) = 80°C
Substituting this values inside the formula to get the final length L2 after expansion, we have;
12 x 10⁻⁶ °C⁻¹ = L2-12/12×80
12 x 10⁻⁶ °C⁻¹ = L2-12/960
L2-12= 960×12 x 10⁻⁶ °C⁻¹
L2-12 = 0.001152
L2 = 12+0.001152
L2 = 12.001152m
Expansion will be the change in length L2-L1 = 12.001152-12
= 0.001152m
The expansion cracks between the slabs should be 0.001152m wide to prevent buckling
Answer:
Magnitude of the Frictional force = (mv₀²)/2x₁
Explanation:
For the frictional force to stop the box, it has to produce the deceleration of the box; thereby being the opposing force to the box's motion.
According to Newton's first law of motion
Frictional force = (mass of the box) × (deceleration experienced by the box)
Let the mass of the box be m
Then,
Frictional force = ma
Then we can obtain the deceleration using the equations of motion
v² = u² + 2ax
u = Initial velocity = v₀ m/s
v = Final velocity = 0 m/s (since the box comes to rest at the end)
x = horizontal distance covered = (x₁ - x₀) = x₁ (since x₀ = 0)
a = ?
v² = u² + 2ax
0 = (v₀)² + 2ax₁
2ax₁ = - v₀²
a = - (v₀²)/(2x₁) (minus sign, because it's a deceleration)
Magnitude of the Frictional force = ma = (mv₀²)/2x₁
<span>example shows that electromagnetic waves can travel without moving through a specific material is
</span>light passing through a vacuum tube
because it shows that there is no medium
so correct option from above is D
hope it helps