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3 years ago

Pa help po science po yan pang grade 7

Physics

1 answer:

AveGali [126]3 years ago

8 0

Answer:

table 1:

1. 100/15 = 6.7 m/s

2. 100/12 = 8.3 m/s

3. 100/9 = 11.1 m/s

table 2:

1. 100/8 = 12.5 m/s

2. 100/6 = 16.7 m/s

3. 100/4 = 25 m/s

Explanation:

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a cylinder has a radius of 2.1cm and a length of 8.8cm .total charge 6.1 x 10^-7C is distributed uniformly throughout. the volum

7nadin3 [17]

The answer for the following problem is explained below.

Therefore the volume charge density of a substance (ρ) is 0.04 × $10^{-1}$ C.

Explanation:

Given:

radius (r) =2.1 cm = 2.1 × $10^{-2}$ m

height (h) =8.8 cm = 8.8 × $10^{-2}$ m

total charge (q) =6.1× $10^{-7}$ C

To solve:

volume charge density (ρ)

We know;

ρ =q ÷ v

volume of cylinder = π ×r × r × h

volume of cylinder =3.14 × 2.1 × 2.1 × $10^{-4}$ × 8.8 × $10^{-2}$

volume of cylinder (v) = 122.23 × $10^{-6}$

ρ =q ÷ v

ρ = 6.1× $10^{-7}$ ÷ 122.23 × $10^{-6}$

ρ = 0.04 × $10^{-1}$ C

Therefore the volume charge density of a substance (ρ) is 0.04 × $10^{-1}$ C.

3 0

3 years ago

You lift a 10-N physics book up in the air a distance of 1.0 m, at a constant velocity

Anarel [89]

The book is lifted upward, but gravity points down, so the work done by gravity must be negative (so you can eliminate options 1 and 3).

The force exerted on the book by gravity has magnitude

F = mg = (10 N) (9.80 m/s^2) = 9.8 N ≈ 10 N

You raise the book 1.0 m in the opposite direction, so the work done is

W = (10 N) (-1.0 m) = -10 J

5 0

3 years ago

What is the wavelength of an earthquake wave if it has a speed of 13 km/s and a frequency of 14 Hz?

Galina-37 [17]

Wavelength = velocity/frequency

wavelength = v/f
v= 13km/s = change this to m/s = 13000m/s
f= 14Hz

wavelength = 13000m/s÷14Hz =928.7 m

8 0

3 years ago

Read 2 more answers

You may have noticed runaway truck lanes while driving in the mountains. These gravel-filled lanes are designed to stop trucks t

Sladkaya [172]

Answer:

0.767

Explanation:

The work done on the truck by the frictional drag force is given by

$W=-Fd$

where

F is the magnitude of the frictional force

d = 38.0 m is the maximum displacement allowed for the truck

The negative sign is due to the fact that the force of friction is opposite to the motion of the truck

The force of friction can also be written as:

$F=\mu mg$

where

$\mu$ is the coefficient of kinetic friction between the truck and the lane

m is the mass of the truck

g is the acceleration of gravity

So we can rewrite the work done as

$W=-\mu mg d$ (1)

According to the work-energy theorem, the work done by friction is equal to the change in kinetic energy of the truck:

$W=K_f - K_i = \frac{1}{2}mv^2-\frac{1}{2}mu^2$ (2)

where

v = 0 is the final velocity of the truck

u = 23.9 m/s is the initial velocity of the truck

By combining (1) and (2) we get

$-\frac{1}{2}mu^2 = -\mu mg d$

And solving for $\mu$ , we find the minimum coefficient of kinetic friction able to stop the truck in a distance d:

$\mu = \frac{u^2}{2gd}=\frac{23.9^2}{2(9.8)(38.0)}=0.767$

7 0

3 years ago

What is the weight of a 1-kilogram brick resting on a table?

MakcuM [25]

Answer:

The weight if the block is 10Newtons

Explanation:

The weight of any object is quantity of matter the object contains and it is always acting downwards on such body. This shows that the object is under the influence of gravity.

The weight of an object is calculated as mass of the object × its acceleration due to gravity

W = mg

Give the mass of the brick to be 1kg

g is the acceleration due to gravity = 10m/s²

Weight of the object = 1 × 10

= 10kgm/s² or 10Newtons

5 0

3 years ago