<span>Th find the average speed of a trip we need to dived the total distance by the total time. Let's find the total distance d. d = (300 mi/h)(2.00 h) + 750 miles d = 600 miles + 750 miles d = 1350 miles The total distance is 1350 miles Let's find the total time t. t = 2.00 hours + (750 mi / 250 mi/h) t = 2.00 hours + 3.00 hours t = 5.00 hours The total time of the trip is 5.00 hours. We can find the average speed. d / t = 1350 miles / 5.00 hours d / t = 270 miles/ hour The average speed of the trip is 270 mi/h (Note that the direction does not matter when we find the average speed.)</span>

6 0

3 years ago

A thin rod of length 1.4 m and mass 140 g is suspended freely from one end. It is pulled to one side and then allowed to swing l

m_a_m_a [10]

Answer:

a The kinetic energy is $KE = 0.0543 J$

b The height of the center of mass above that position is $h = 1.372 \ m$

Explanation:

From the question we are told that

The length of the rod is $L = 1.4m$

The mass of the rod $m = 140 = \frac{140}{1000} = 0.140 \ kg$

The angular speed at the lowest point is $w = 1.09 \ rad/s$

Generally moment of inertia of the rod about an axis that passes through its one end is

$I = \frac{mL^2}{3}$

Substituting values

$I = \frac{(0.140) (1.4)^2}{3}$

$I = 0.0915 \ kg \cdot m^2$

Generally the kinetic energy rod is mathematically represented as

$KE = \frac{1}{2} Iw^2$

$KE = \frac{1}{2} (0.0915) (1.09)^2$

$KE = 0.0543 J$

From the law of conservation of energy

The kinetic energy of the rod during motion = The potential energy of the rod at the highest point

Therefore

$KE = PE = mgh$

$0.0543 = mgh$

$h = \frac{0.0543}{9.8 * 0.140}$

$h = 1.372 \ m$

5 0

2 years ago

Read 2 more answers

The height of the Washington Monument is measured to be 170 m on a day when its temperature is 35.0°C. What will the change in i

Alecsey [184]

Answer:

The deformation is 0.088289 m

The final height of the monument is 170-0.088289 = 169.911702 m

Explanation:

Thermal coefficient of marble varies between (5.5 - 14.1) ×10⁻⁶/K = α

So, let us take the average value

(5.5+14.1)/2 = 9.8×10⁻⁶ /K

Change in temperature = 35-(-18) = 53 K = ΔT

Original length = 170 m = L

Linear thermal expansion

$\frac{\Delta L}{L} = \alpha\Delta T\\\Rightarrow \Delta L=\frac{\alpha\Delta T}{L}\\\Rightarrow \Delta L=9.8\times 10^{-6}\times 53\times 170$

The deformation is 0.088289 m

The final height of the monument is 170-0.088289 = 169.911702 m (subtraction because of cooling)

4 0

2 years ago

a body starts from rest with a uniform acceleration of 2m s-2 find the distance covered by the body in 2s

Evgen [1.6K]

Finding acceleration= final velocity-initial velocity/ time taken (or A= V-U/T)

Final speed= 2m
Initial speed= 0m
Time taken= 2 seconds

2-0/2 so it’ll be 1m/s

2-0=0
2/2=

8 0

2 years ago