Answer:
a = 0.50 m/s²
v = 6.0 m/s
Explanation:
Step 1: Given data
- Initial velocity (u): 0 m/s (rest)
- Displacement of the marble (s): 36 m
Step 2: Calculate the acceleration
We will use the following suvat equation.
s = u × t + 1/2 × a × t²
s = 0 × 12.0 s + 1/2 × a × (12.0 s)²
36 m = a × 72.0 s²
a = 0.50 m/s²
Step 3: Calculate the final velocity
We will use the following suvat equation.
v = u + a × t
v = 0 + 0.50 m/s² × 12.0 s
v = 6.0 m/s
Answer:
v = 3.6m / s
, θ = 56º
Explanation:
This is a relative speed exercise, let's use the Pythagorean theorem
v = √ (v₁² + v₂²)
where v₁ is the speed of the sea still water and v₂ the speed of the current
let's calculate
v = √ (2² + 3²)
v = 3.6m / s
to find the direction we use trigonometry
tan θ = v₂ / v₁
θ = tan⁻¹ (v₂ / v₁)
let's calculate
θ = tan⁻¹ (3/2)
θ = 56º
Answer:
The ball will reach the ground in 0.8s
Option C
Explanation:
Given:
- Takes t = 0.8 s for ball to reach ground when thrown horizontal from top of a building.
Find:
If it had been thrown with twice the speed in the same direction, it would have hit the ground in how many second.
Solution:
- We know that the amount of time taken to hit the ground is determined by the vertical distance i.e height at which it is thrown. The displacement of ball from top is given by:
S_y = S_o + V_i,y*t + 0.5*g*t^2
- We know that the S_o = height of the building.
We also know that the ball os thrown horizontally; hence, y-component of initial velocity is zero. V_y,i = 0
0 = h + 0 + 0.5*g*t^2
- Hence, the time taken t is:
t = sqrt ( 2h / g)
- The time taken to reach the ground is independent of the initial speed. Hence, the ball will reach the ground in 0.8s .
<span>The answer is physical change. This is a kind of change moving the form of a chemical substance, but not its chemical arrangement. Physical changes are used to isolate combinations into their constituent compounds, but cannot typically be used to distinct compounds into chemical elements or simpler compounds. When the salt dissolve in water it is a physical change. The chemical arrangement of the salt is not altered.</span>
