Answer:
As the trailer leaks sand at a constant rate through a hole in its bottom, its acceleration increases at a steady rate. (Option A)
Explanation:
F = ma
where;
F is the force applied on the truck
m is the mass of the truck
a is the acceleration of the truck
If the driving force on the truck remain constant, then;
m₁a₁ = m₂a₂
a₁ is the initial acceleration
a₂ is the final acceleration
m₁ is the initial mass of the truck and loaded sand,
m₂ is the final mass of the truck and loaded sand, which decreases as the sand leaks at a constant rate.
a₂ = (m₁a₁ )/(m₂)
since m₁ > m₂, a₂ > a₁
Therefore, as the trailer leaks sand at a constant rate through a hole in its bottom, its acceleration increases at a steady rate.
Answer with Explanation:
We are given that
Weight of an ore sample=17.5 N
Tension in the cord=11.2 N
We have to find the total volume and the density of the sample.
We know that
Tension, T=
=buoyancy force
T=Tension force
W=Weight
By using the formula
N
Where
=Volume of object
=Density of water
=Acceleration due to gravity
Substitute the values then we get
Volume of sample=
Density of sample,
Where mass of ore sample=1.79 kg
Substitute the values then, we get
Density of the sample=
Answer:
Gwen’s assumption of asteroid hit as long term change is incorrect. Asteroid hit is not a long term change, instead, it is a short term change.
Explanation:
Examples of short term changes are drought, flood, volcanic eruption, etc. A short term change occurs quickly and can immediately affect organisms but it doesn’t become a reason for species extinction. The effects of a short term change don’t prevail over a long span of time.
Examples of long term changes are ice age, global warming, deforestation, etc. Unlike a short term change, it takes time but the consequences are far-reaching. It can lead to species extinction.
In this question, asteroid hit is a quick and unexpected hazard, unlike the slow long term environmental changes.
Answer:
4.8 m/s
Explanation:
When she catches the train,
- They will have travelled the same distance.and
- Their speeds will be equal
The formula for the distance covered by the train is
d = ½at² = ½ × 0.40t² = 0.20t²
The passenger starts running at a constant speed 6 s later, so her formula is
d = v(t - 6.0)
The passenger and the train will have covered the same distance when she has caught it, so
(1) 0.20t² = v(t - 6.0)
The speed of the train is
v = at = 0.40t
The speed of the passenger is v.
(2) 0.40t = v
Substitute (2) into (1)
0.20t² = 0.40t(t - 6.0) = 0.40t² - 2.4 t
Subtract 0.20t² from each side
0.20t² - 2.4t = 0
Factor the quadratic
t(0.20t - 2.4) = 0
Apply the zero-product rule
t =0 0.20t - 2.4 = 0
0.20t = 2.4
(3) t = 12
We reject t = 0 s.
Substitute (3) into (2)
0.40 × 12 = v
v = 4.8 m/s
The slowest constant speed at which she can run and catch the train is 4.8 m/s.
A plot of distance vs time shows that she will catch the train 6 s after starting. Both she and the train will have travelled 28.8 m. Her average speed is 28.8 m/6 s = 4.8 m/s.
Answer:
student 1 is right and student 2 is wrong
Explanation:
In the graph that the two students are observing is a graph of energy and frequency vs. wavelength, this graph is constructed using the relationship between a wave and its wavelength and frequency.
c = λ f
therefore for all waves we have the speed salami.
Therefore student 1 is right and student 2 is wrong