Explain why the speed of a sled is increases as it moves down a snow -covered hill, even though no one is pushing the sled

Natali [406]

You are exerting 100N. Since there’s no NET force, then there must be exactly 100N pushing exactly back on your 100N to cancel it to exactly zero. Newton's first law states that whether a body is at rest or travelling in a straight line at a constant speed, it will remain at rest or continue to move in a straight line at a constant speed unless acted upon by a force.

8 0

2 years ago

The magnetic field at the centre of a toroid is 2.2-mT. If the toroid carries a current of 9.6 A and has 6.000 turns, what is th

ziro4ka [17]

Answer:

Radius, r = 0.00523 meters

Explanation:

It is given that,

Magnetic field, $B=2\ mT=2.2\times 10^{-3}\ T$

Current in the toroid, I = 9.6 A

Number of turns, N = 6

We need to find the radius of the toroid. The magnetic field at the center of the toroid is given by :

$B=\dfrac{\mu_oNI}{2\pi r}$

$r=\dfrac{\mu_oNI}{2\pi B}$

$r=\dfrac{4\pi \times 10^{-7}\times 6\times 9.6}{2.2\pi \times 2\times 10^{-3}}$

r = 0.00523 m

or

$r=5.23\times 10^{-3}\ m$

So, the radius of the toroid is 0.00523 meters. Hence, this is the required solution.

7 0

2 years ago

Read 2 more answers

Distinguish between force and friction. class 8

KengaRu [80]

Answer: Friction is the resistance to motion of one object moving relative to another. For example, when you try to push a book along the floor, friction makes this difficult. Force: Force is essentially a push, or a pull action, that can lead to certain outcomes.

7 0

2 years ago

For a given wave IF frequency doubles the wavelength

motikmotik

Answer:

C is halved

Explanation:

The frequency and the wavelength of a wave are related by the equation:

$v=f\lambda$

where

v is the speed of the wave

f is the frequency

$\lambda$ is the wavelength

From the equation above, we see that for a given wave, if the wave is travelling in the same medium (and so, its speed is not changing), then the frequency and the wavelength are inversely proportional to each other.

Therefore, if the frequency doubles, the wavelength will halve in order to keep the speed constant:

$\lambda = \frac{v}{f}\\\lambda' = \frac{v}{f'}=\frac{v}{2f}=\frac{1}{2}(\frac{v}{f})=\frac{\lambda}{2}$

7 0

3 years ago

Two cars are moving in the same direction at the same speed of (72.0 kmh). What is

Licemer1 [7]

Answer:

0 km/h

Explanation:

Relative speed is the speed of a moving body with respect to another.

When two bodies move in the same direction then the relative speed is calculated as difference of their speeds.

In this case;

The two cars have the same speed. The relative speed will be;

72 km/h -72 km/h = 0 km/h

6 0

2 years ago