Answer:
2. ( b ) zero
3. ( c ) 10 s
4. Uniform then decreasing
Explanation:
2.
Since the motion is uniform, initial and final velocity will be 0, hence acceleration will be zero.
3.
Initial velocity ( u ) = 5 m/s
Final velocity ( v ) = 35 m/s
Acceleration ( a ) 3 m/s^2
To find : Time ( t )
Formula : -
t = v - u / a
= 35 - 5 / 3
= 30 / 3
t = 10 s
When the bus starts moving forward, the man remains at rest,
causing him to lean back.
When the bus slows down, the man continues to move forward,
and appears to lean forward.
Both events are examples of the effect of inertia.
The area of a square is given by:
A = s²
A is the square's area
s is the length of one of the square's sides
Let us take the derivative of both sides of the equation with respect to time t in order to determine a formula for finding the rate of change of the square's area over time:
d[A]/dt = d[s²]/dt
The chain rule says to take the derivative of s² with respect to s then multiply the result by ds/dt
dA/dt = 2s(ds/dt)
A) Given values:
s = 14m
ds/dt = 3m/s
Plug in these values and solve for dA/dt:
dA/dt = 2(14)(3)
dA/dt = 84m²/s
B) Given values:
s = 25m
ds/dt = 3m/s
Plug in these values and solve for dA/dt:
dA/dt = 2(25)(3)
dA/dt = 150m²/s
Answer:
F = 2074.13 lb
Explanation:
Given that,
Mass of car, m = 2800 lb = 1270.059 kg
Initial speed, u = 5 mi/h = 2.2352 m/s
Final speed, v = - 1.5 mi/h = -0.67056 m/s (in opposite direction)
Time, t = 0.4 s
We need to find the magnitude of the average horizontal force (lb) exerted on the car during the impact. It can be calculated as :

or
F = -2074.13 lb
So, the required force is 2074.13 lb.
-- kiloliter ... 1000 liters
-- megaliter ... 1 million liters
Those two are the only ones on the list that are bigger than 1 liter.
The others:
-- milli- ... 0.001
-- deci- ... 0.1
-- centi- ... 0.01
-- nano- ... 0.000 000 001