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3 years ago

Choose the false statement regarding resistance.

Physics

2 answers:

konstantin123 [22]3 years ago

5 0

Answer:

I think is C

Please mark me as brainliest

Afina-wow [57]3 years ago

4 0

Answer:

i think D I hope this helps!!!!

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A Canyon ball is fired from the ground level in angle of 35 from the ground at a speed of 150 m/s ignore air resistance calculat

Virty [35]

The velocity, 50 m/s, has two components - vertical and horizontal velocities.

The vertical component = 50 sin 30 = 25 m/s

The horizontal component = 50 cos 30 = 43.3 m/s

(a) Let t be the time taken for the vertical component to reach its peak from initial velocity = 25 m/s to its final velocity = 0.

Using the linear motion equation v = u - gt

0 = 25 - 10t

t = 2.5 s

Time taken to go up and down = 5 s

Time to hit the ground = 5 s

(b) Horizontal distance dealt x = 43.3 * 5 = 216.5 m

This is not the correct answer, but explains the problem thoroughly.

7 0

3 years ago

Air at 27oC and 1 atm flows over a flat plate 40 cm in length and 1 cm in width at a speed of 2 m/s. The plate is heated over it

irga5000 [103]

Answer:

Heat transferred = 22.9 watt

Explanation:

Given that:

$T_1$ = 27°C = (273 + 27) K = 300 K

$T_2$ = 600°C = (600 +273) K = 873 K

speed v = 2 m/s

length x = 40 cm = 0.4 cm

width = 1 cm = 0.001 m

The heat transferred from the plate can be calculate by using the formula:

Heat transferred = h×A ×ΔT

From the tables of properties of air, the following values where obtained.

$k = 0.02476 \ W/m.k \\ \\ \rho = 1.225 \ kg/m^3 \\ \\ \mu = 18.6 \times 10^{-6} \ Pa.s \\ \\ c_p = 1.005 \ kJ/kg$

To start with the reynolds number; the formula for calculating the reynolds number can be expressed as:

reynolds number = $\dfrac{\rho \times v \times x }{\mu}$

reynolds number = $\dfrac{1.225 \times 2 \times 0.4}{18.6 \times 10^{-6}}$

reynolds number = $\dfrac{0.98}{18.6 \times 10^{-6}}$

reynolds number = 52688.11204

Prandtl number = $\dfrac{c_p \mu}{k}$

Prandtl number = $\dfrac{1.005 \times 18.6 \times 10^{-6} \times 10^3}{0.02476}$

Prandtl number = $\dfrac{0.018693}{0.02476}$

Prandtl number = 0.754963

The nusselt number for this turbulent flow over the flat plate can be computed as follows:

Nusselt no = $\dfrac{hx}{k} = 0.0296 (Re) ^{0.8} \times (Pr)^{1/3}$

$\dfrac{h \times 0.4}{0.02476} = 0.0296 (52688.11204) ^{0.8} \times (0.754968)^{1/3}$

$\dfrac{h \times 0.4}{0.02476} =161.4252008}$

$h =\dfrac{161.4252008 \times 0.02476}{ 0.4}$

h = 9.992 W/m.k

Recall that:

The heat transferred from the plate can be calculate by using the formula:

Heat transferred = h×A ×ΔT

Heat transferred = $h\times A \times (T_2-T_1)$

Heat transferred = 9.992 × (0.4 × 0.01) ×(873-300)

Heat transferred = 22.9 watt

6 0

3 years ago

Ariel's puppy weighs 15 lb. Heather's puppy weighs 50 N. Whose puppy weighs more?

yarga [219]

15 lb is nearly 6 kg amd 50 n is nearly 5 kg,so first puppy weighs more

5 0

3 years ago

How many protons, neutrons, and electrons does a neutral atom of this element have? (round atomic mass to nearest whole number)

adelina 88 [10]

Answer:

The element "AI" has:

Protons: 13 Neutrons: 14 Electrons: 13

Have a great day.

8 0

3 years ago

Read 2 more answers

How do you calculate acceleration

AfilCa [17]

A=f/m
Example a=10/2
A=5

7 0

3 years ago

Read 2 more answers