All categories

3 years ago

You drive your car from home at an

Physics

1 answer:

kondaur [170]3 years ago

3 0

Answer:

60 km/h

Explanation:

In the first part of the trip, the speed is

v = 80 km/h

while the time interval is

t = 3 h

So, the distance covered is:

d = vt = (80)(3)= 240 km

The problem states that this distance is half distance between home and the destination - so, the total distance between home and the destination is

$D=2d=2(240)=480 km$

The time taken to cover the second part of the trip is 5 h, so the total time taken is

T = 3 h + 5 h = 8 h

Therefore, the average velocity for the entire trip is

$v=\frac{D}{T}=\frac{480}{8}=60 km/h$

You might be interested in

The idea that the universe began from a single point and expanded to its current size explains a large number of observations, i

murzikaleks [220]

The description of the question provided above points out to the famous Big Bang Theory. In addition, this theory is among the most accepted by cosmologists because it fits like a glove to the phenomenon the universe is experiencing right now: it is expanding and distances between celestial bodies are getting farther and farther.

6 0

4 years ago

Read 2 more answers

The gravitational force,F, on a rocket at a distance,r, from the center of the earth isgiven byF=kr2wherek= 1013N·km2. (Newton·k

Brrunno [24]

Answer:

The gravitational force changing velocity is

$\frac{dF}{dt}=-8\frac{N}{s}$

Explanation:

The expression for the gravitational force is

$F=\frac{k}{r^{2}}\\\\k=10x10^{13} N*km^{2}\\\\r=10x10^{4} km\\\\V=0.4 \frac{km}{s}$

Differentiate the above equation

$\frac{dF}{dt}=\frac{k}{r^{2}}\\\frac{dF}{dt}=k*r^{-2}\\\frac{dF}{dt}=-2*k*r^{-3} \frac{dr}{dt}\\\frac{dF}{dt}=\frac{-2k}{r^{3}}\frac{dr}{dt}$

The velocity is the distance in at time so

$V=\frac{dr}{dt}=0.4 \frac{km}{s}$

$\frac{dF}{dt}=\frac{-2*k}{r^{3}}*0.4\\\frac{dF}{dt}=\frac{-8*10x^{13}N*km^{2} }{(10x10^{4}) ^{3}} \\\frac{dF}{dt}=\frac{-8x10^{12} }{1x10^{12}}$

$\frac{dF}{dt}=-8\frac{N}{s}$

8 0

4 years ago

Why skies are blue but not other colours

wolverine [178]

Answer:

The Short Answer: Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.

Explanation:

4 0

3 years ago

A skater of mass 40 kg is carrying a box of mass 5 kg. The skater has a speed of 5 m/s with respect to the floor and is gliding

Yuki888 [10]

For the part a) we need only the momentum of the box and we have the data to find it.

Momentum is given by,

$p=mv$

where clearly, p is the momentum, m the mass of the box and v is the velocity.

Substituting,

$p=(5kg)(5m/s)\\p=25kg.m/s$

For part b) we need an analysis of the situation. We understand that the box on a surface that has no friction will continue to rotate at the same speed previously defined. The box can only stop with friction, so,

$p=(5kg)(5m/s)\\p=25kg.m/s$

8 0

3 years ago

a u tube contains a liquid of an unknown density an oil of density is poured into the right arm of the tube until the oil column

scoray [572]

Answer:

The answer is " $1155\ \frac{kg}{m^3}$ "