All categories

2 years ago

you drive in a straight line at 20.0m/s for 10.0 min, then 30.0m/s for another 10.0 min. Find the average speed.

Physics

1 answer:

Juliette [100K]2 years ago

6 0

Answer is 25 m/s.

Explanation;

Step 1 : Convert the units into same unit.

Here speeds are given in m/s while the time is in minutes. So, let's convert minutes into seconds.

1 min = 60 s

Then,

10 minutes = 10 x 60 s = 600 s

Step 2 : Find the total distance that you have travelled.

To find that you need to first find distances separately.

We know the formula, s = vt, where s is the distance, v is the speed or velocity and t is the time.

First you have travelled 10 minutes (600 s) at 20.0 m/s.

Then distance, s = 20.0 m/s x 600 s = 12 000 m

Secondly you have travelled again 10 minutes at 30.0 m/s

Then distance = 30.0 m/s x 600 s = 18 000 m

Then, the total distance = 12 000 m + 18 000 m = 30 000 m

Step 3 : Find the total time taken to travel.

Total time = 600 s + 600 s = 1200 s

Step 4 : Calculate the average speed.

Average speed = total distance / total time

= 30 000 m / 1200 s

= 25 m/s

You might be interested in

Suppose you place a ball in the middle of a wagon, and then accelerate the wagon forward. Describe the motion of the ball relati

rjkz [21]

Answer:

The motion of the ball relative to the ground is stationary

The motion of the ball relative to the wagon is backwards

Explanation:

To describe the motion of the ball relative to the ground, we note that

Assuming the ball is perfectly round and rotate freely, then we have

Force on the ball due to motion of the wagon = 0 N,

Then by the law of motion, an object will remain at rest when no force is applied to it

Therefore, apart from rotation of the ball, it will remain no displacement relative to the ground.

The motion of the ball relative to the wagon

Relative to the wagon, the ball appears to be moving in the opposite direction to the wagon, that is backwards.

4 0

3 years ago

Read 2 more answers

Physicists and engineers from around the world have come together to build the largest accelerator in the world, the Large Hadro

elena-14-01-66 [18.8K]

Solution :

Energy of photon, E = 6.7 eV

E = $6.7 \times 1.602 \times 10^{-7}$ joule

Kinetic energy, $K.E. =\frac{1}{2} mv^2 = 1.602 \times 6.7 \times 10^{-7}$

$v^2=\frac{2 \times 1.602 \times 6.7 \times 10^{-7}}{1.6726 \times 10^{-27}}$

$=12.834 \times 10^{-20}$

Kinetic energy at high speeds

$(r-1)\times mc^2 = 6.7 \ eV$

$(r-1)=\frac{6.7 \times 1.602 \times 10^{-7}}{1.6726 \times 10^{-27} \times 9 \times 10^{16}}$

r - 1 = 7130

r = 7130 + 1

r = 7131

$\frac{1}{\sqrt{1-\frac{v^2}{C^2}}}=7131$

$1-\frac{v^2}{C^2} = \left(\frac{1}{7131}\right)^2$

$v^2=C^2\left[1-\left(\frac{1}{7131}\right)^2\right]$

$v=0.99999999017C$

Δ = 1 - 0.99999999017

= 0.00000000933

Relative mass, $m_{rel}=r.m$

$=7131 \times 1.6728 \times 10^{-27}$

$=1.1927 \times 10^{-23}$ kg

6 0

2 years ago

What is the substance that is broken down in cellular respiration

Harman [31]

Glucose.... have a nice day

4 0

3 years ago

Derivation 1.2 showed how to calculate the work of reversible, isothermal expansion of a perfect gas. Suppose that the expansion

stellarik [79]

Answer:

(a) The work done by the gas on the surroundings is, 17537.016 J

(b) The entropy change of the gas is, 73.0709 J/K

Explanation:

(a) The expression used for work done in reversible isothermal expansion will be,

where,

w = work done = ?

n = number of moles of gas = 4 mole

R = gas constant = 8.314 J/mole K

T = temperature of gas = 240 K

= initial volume of gas =

= final volume of gas =

Now put all the given values in the above formula, we get:

The work done by the gas on the surroundings is, 17537.016 J

(b) Now we have to calculate the entropy change of the gas.

As per first law of thermodynamic,

where,

= internal energy

q = heat

w = work done

As we know that, the term internal energy is the depend on the temperature and the process is isothermal that means at constant temperature.

So, at constant temperature the internal energy is equal to zero.

Thus, w = q = 17537.016 J

Formula used for entropy change:

The entropy change of the gas is, 73.0709 J/K

(c) Now we have to calculate the entropy change of the gas when the expansion is reversible and adiabatic instead of isothermal.

As we know that, in adiabatic process there is no heat exchange between the system and surroundings. That means, q = constant = 0

So, from this we conclude that the entropy change of the gas must also be equal to zero.

Explanation:

6 0

2 years ago

An unknown fluid has a specific gravity of 0.750. What is the volume of 22.5 kg of this fluid?

Andru [333]

<h2>Option C is the correct answer.</h2>

Explanation:

Specific gravity of fluid = 0.750

Density of fluid = Specific gravity of fluid x Density of water

Density of fluid = 0.750 x 1000

Density of fluid = 750 kg/m³

Mass of fluid = 22.5 kg

We have

Mass = Volume x Density

22.5 = Volume x 750

Volume = 0.03 m³ = 30 L

Option C is the correct answer.

5 0

3 years ago