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borishaifa [10]

3 years ago

13

a car travel uniformly speed of 30 km/h for 30 minutes and then at uniform speed of 60km/h for next 30min calculate the average

speed of car

1 answer:

algol133 years ago

3 0

Explanation:

i hope this will help you

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A fisherman notices that his boat is moving up and down periodically without any horizontal motion, owing to waves on the surfac

Sedbober [7]

Answer:

v = 1.2 m/s

Explanation:

The wavelength of the waves is given as the horizontal distance between the crests:

λ = wavelength = 5.5 m

Now, the time period is given as the time taken by boat to move from the highest point again to the highest point. So it will be equal to twice the time taken by the boat to travel from highest to the lowest point:

T = Time Period = 2(2.3 s) = 4.6 s

Now, the speed of the wave is given as:

$v = f\lambda$

where,

v= speed of wave = ?

f = frequency of wave = $\frac{1}{T} = \frac{1}{4.6\ s} = 0.217\ Hz$

Therefore,

$v = (0.217\ Hz)(5.5\ m)\\$

<u>v = 1.2 m/s</u>

5 0

3 years ago

If my cylinder of air lasts 60 minutes while I am at the surface breathing normally, assuming all else is the same, how long wil

AfilCa [17]

Answer:

Explanation:

Let the volume of air be V. at atmospheric pressure, that is 10⁵ Pa

At 20 m below surface pressure will be

atmospheric pressure + hdg

10⁵ + 20 x 9.8 x 1000 = 2.96 x 10⁵Pa

At this pressure volume V becomes V/ 2.96

This volume will last 1/2.96 times time that is 60/2.96 = 20.27 minutes.

8 0

3 years ago

Newton’s Second Law of motion defines force in terms of mass and acceleration, F= ma. Which of the following is false? The term

NikAS [45]

Answer:

The forces creating the net force must lie in the same direction.

Explanation:

newton's second law states that the net force acting on the body is equal to the product of mass and the acceleration of the body.

If there are several forces acting on the body in different directions, then we have to find teh net force by using the vector sum and then find the acceleration.

It is not necessary that all the forces acting in the same direction.

if they are in different directions then we have to find the net force by t=using the formula for the vector sum.

5 0

4 years ago

A ball with an initial velocity of 8.00 m/s rolls up a hill without slipping. (a) Treating the ball as a spherical shell, calcul

GrogVix [38]

Answer:

Part i)

h = 5.44 m

Part ii)

h = 3.16 m

Explanation:

Part i)

Since the ball is rolling so its total kinetic energy in this case will convert into gravitational potential energy

So we have

$\frac{1}{2}mv^2 + \frac{1}{2}I\omega^2 = mgh$

here we know that for spherical shell and pure rolling conditions

$v = R \omega$

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

$\frac{1}{2}mv^2 + \frac{1}{2}(\frac{2}{3}mR^2)(\frac{v^2}{R^2}) = mgh$

$\frac{5}{6}mv^2 = mgh$

$h = \frac{5v^2}{6g}$

$h = \frac{5(8^2)}{6(9.81)} = 5.44 m$

Part b)

If ball is not rolling and just sliding over the hill then in that case

$\frac{1}{2}mv^2 = mgh$

$h = \frac{v^2}{2g}$

$h = \frac{8^2}{2(9.81)} = 3.16 m$

3 0

3 years ago

What is a small body that follows a highly elliptical orbit around the Sun

Ipatiy [6.2K]

That could be a comet, or any one of the billions of meteoroids
moving in a cloud that's actually the remains of a shattered comet.

6 0

3 years ago

Read 2 more answers