All categories

3 years ago

In a simple machine, what does it mean :i) If efficiency is said to be 65%.

2 answers:

8 0

It is an real machine because if efficiency is below100% it is real machine but if efficiency is 100% it is an ideal machine

hichkok12 [17]3 years ago

7 0

This machine is has an efficiency of 65% which means the machines is ok not that efficient

You might be interested in

a woman walks south at a speed of 2.0mph for 60 minutes. She then turns around and walks north at a distance of 3000m in 25 minu

TiliK225 [7]

When a woman walks south at a speed of 2.0mph for 60 minutes. She then turns around and walks north at a distance of 3000m in 25 minutes. then the woman's average speed during her entire motion would be 73.15 meters /minute.

<h3>What is speed?</h3>

The total distance covered by any object per unit of time is known as speed.

the mathematical expression for speed is given by

speed = total; distance /total time

As given in the problem a woman walks south at a speed of 2.0mph for 60 minutes

60 min = 1 hour

1 mile = 1.60934 km

The distance covered by her southwards = speed ×time

=2 mph × 60 minutes

= 3.218 km

She then turns around and walks north at a distance of 3000m in 25 minutes

The distance covered northward is 3000m

speed = total distance /total time

=(3218 +3000) /(60+25)

=73.15 meters /minutes

Thus, The average speed of the woman would be 73.15 meters /minute.

Learn more about speed from here

brainly.com/question/13263542

#SPJ1

8 0

1 year ago

The position of a dragonfly that is flying parallel to the ground is given as a function of time by r⃗ =[2.90m+(0.0900m/s2)t2]i^

Arlecino [84]

The solution for this problem is:

r = [(2.90 + 0.0900t²) i - 0.0150t³ j] m/s²
this is for t in seconds and r in meters

v = dr/dt = [0.180t i - 0.0450t² j] m/s²

tan(-36.0º) = -0.0450t² / 0.180t
0.7265 = 0.25t
t = 2.91 s is the velocity vector of the insect

7 0

3 years ago

Read 2 more answers

You throw a bouncy rubber ball and a wet lump of clay, both of mass m, at a wall. Both strike the wall at speed v, but while the

lana [24]

Answer:

<em>The fifth option is the correct answer: mv; 2 mv</em>

Explanation:

<u>Change of Momentum</u>

Assume an object has a momentum p1 and after some interaction it now has a momentum p2, the change of momentum is

$\Delta p=p_2-p_1$

The momentum is computed as

$p=mv$

Where m is the mass of the object and v its speed. Now let's analyze the situation of both the ball and the clay.

The clay has an initial speed v and a mass m, thus its initial momentum is

$p_1=mv$

When it hits the wall, it sticks, thus its final speed is 0 and

$p_2=0$

The change of momentum is

$\Delta p=0-mv=-mv$

The absolute change is mv

Now for the ball, the initial condition is the same as it was for the clay, but the ball hits back at the same speed, thus its final momentum is

$p_2=-mv$

The change of momentum is

$\Delta p=-mv-mv=-2mv$

The absolute change is 2mv

The fifth option is the correct answer: mv; 2 mv

3 0

3 years ago

Can anybody help me please?

vovangra [49]

Answer:

1,2,5

Explanation:

7 0

2 years ago

Name each planet in the solar system

satela [25.4K]

Mercury is the closest planet to the sun.

Venus is second planet. Venus has no moons.

Earth is the third planet. This is the only planet that is known to inhabit life.

Mars is the fourth planet. Mars is called the "red planet" and has two moons.

Jupiter is the fifth planet in our solar system. Jupiter is the biggest planet in our solar system.

Saturn is the sixth planet. It has 31 moons.

Uranus is the seventh planet. It is a greenish-blue planet.

Neptune is the eight planet. On Neptune, temperatures stay colder than -350 Fahrenhiet.

Pluto is no longer a planet, but if you weighed 100 pounds on Earth, then you would weight 7-8 pounds on Pluto. But your mass would be the same.

5 0

3 years ago