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3 years ago

The force that slows down a soccer ball rolling on the grass is the same force used to start a campfire. True or False

Physics

2 answers:

Kay [80]3 years ago

6 0

The answer is Falseim pretty sure

Stels [109]3 years ago

3 0

Answer:

True

Explanation:

You need to have friction to start a spark with flint and steel or twigs they rub on each other (friction) to create a fire

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A circular loop of radius 13 cm carries a current of 13 A. A flat coil of radius 0.94 cm, having 58 turns and a current of 1.9 A

telo118 [61]

Answer:

$6.28\times 10^{-5}\ \text{T}$

$1.92\times 10^{-6}\ \text{Nm}$

Explanation:

$\mu_0$ = Vacuum permeability = $4\pi 10^{-7}\ \text{H/m}$

$I_l$ = Current in circular loop = 13 A

$r_l$ = Radius of circular loop = 13 cm

$N$ = Number of turns = 58

$r_c$ = Radius of coil = 0.94 cm

$I_c$ = Current in coil = 1.9 A

$\theta$ = Angle between loop and coil = $90^{\circ}$

Magnitude of magnetic field in circular loop

$B_l=\dfrac{\mu_0I_l}{2r_l}\\\Rightarrow B_l=\dfrac{4\pi 10^{-7}\times 13}{2\times 13\times 10^{-2}}\\\Rightarrow B_l=6.28\times 10^{-5}\ \text{T}$

The magnetic field produced by the loop at its center is $6.28\times 10^{-5}\ \text{T}$ .

Torque is given by

$\tau=\pi NI_cr_c^2B_l\sin\theta\\\Rightarrow \tau=\pi 58\times 1.9\times (0.94\times 10^{-2})^2\times 6.28\times 10^{-5}\sin90^{\circ}\\\Rightarrow \tau=1.92\times 10^{-6}\ \text{Nm}$

The torque on the coil due to the loop $1.92\times 10^{-6}\ \text{Nm}$ .

8 0

3 years ago

please answer 1-3 and use a separate piece of paper thank you i've been trying those problems for 3 day.... ikr Sad

11Alexandr11 [23.1K]

$\frac{total distance}{ total time}$

$\frac{72m}{36s} = 2m/s$

Same thing for the rest
2) 5km/h
3)360km/h

4 0

3 years ago

A student conduct an experiment to determine habitation of salt to water affect the density of the water the student feels three

Nikolay [14]

Any like answer choices would be helpful '-'

8 0

3 years ago

If the position of a particle on the x-axis at time t is âˆ’5t2, then the average velocity of the particle for 0 â‰¤ t â‰¤ 3 is

Drupady [299]

Answer:

v = 15 m / s

Explanation:

In this exercise we are given the position function

x = 5 t²

and we are asked for the average velocity in an interval between t = 0 and t= 3 s, which is defined by the displacement between the time interval

$v= \frac{v_{f} - v_{o} }{t_{f} - t_{o} }$

let's look for the displacements

t = 0 x₀ = 0 m

t = 3 $x_{f}$ = 5 3 2

x_{f} = 45 m

we substitute

$v = \frac{45 -0}{3 - 0}$

v = 15 m / s

3 0

3 years ago

What is the density of a substance that has a mass of 453g and a volume of 224mL?

Mrrafil [7]

Density is mass per unit volume. In this case, the unit is g/ml
Mass=453g ρ=453g/224ml
Volume=224ml ρ=2.022g/ml(rounded to nearest hundredth)
Density=?
ρ=mass/volume
Therefore the density of the substance is 2.022g/ml

6 0

3 years ago