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2 years ago

Between the ball and the player’s head, there are forces. Which of Newton’s laws does this represent? Support your choice.

Physics

2 answers:

Nana76 [90]2 years ago

8 0

Answer:according to newtons third law for every action force there is an equal in size and opposite in direction reaction force forces always comes in pairs

Explanation:

ira [324]2 years ago

7 0

I need help with this one to

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A projectile is fired into the air from the top of a 200-m cliff above a valley as shown below. Its initial velocity is 60 m/s a

anastassius [24]

a) y(max) = 337.76 m

b) t₁ = 5.30 s the time for y maximum

c)t₂ = 13.60 s time for y = 0 time when the fly finish

d) vₓ = 30 m/s vy = - 81.32 m/s

e)x = 408 m

Equations for projectile motion:

v₀ₓ = v₀ * cosα v₀ₓ = 60*(1/2) v₀ₓ = 30 m/s ( constant )

v₀y = v₀ * sinα v₀y = 60*(√3/2) v₀y = 30*√3 m/s

a) Maximum height:

The following equation describes the motion in y coordinates

y = y₀ + v₀y*t - (1/2)*g*t² (1)

To find h(max), we need to calculate t₁ ( time for h maximum)

we take derivative on both sides of the equation

dy/dt = v₀y - g*t

dy/dt = 0 v₀y - g*t₁ = 0 t₁ = v₀y/g

v₀y = 60*sin60° = 60*√3/2 = 30*√3

g = 9.8 m/s²

t₁ = 5.30 s the time for y maximum

And y maximum is obtained from the substitution of t₁ in equation (1)

y (max) = 200 + 30*√3 * (5.30) - (1/2)*9.8*(5.3)²

y (max) = 200 + 275.40 - 137.64

y(max) = 337.76 m

Total time of flying (t₂) is when coordinate y = 0

y = 0 = y₀ + v₀y*t₂ - (1/2)* g*t₂²

0 = 200 + 30*√3*t₂ - 4.9*t₂² 4.9 t₂² - 51.96*t₂ - 200 = 0

The above equation is a second-degree equation, solving for t₂

t = [51.96 ±√ (51.96)² + 4*4.9*200]/9.8

t = [51.96 ±√2700 + 3920]/9.8

t = [51.96 ± 81.36]/9.8

t = 51.96 - 81.36)/9.8 we dismiss this solution ( negative time)

t₂ = 13.60 s time for y = 0 time when the fly finish

The components of the velocity just before striking the ground are:

vₓ = v₀ *cos60° vₓ = 30 m/s as we said before v₀ₓ is constant

vy = v₀y - g *t vy = 30*√3 - 9.8 * (13.60)

vy = 51.96 - 133.28 vy = - 81.32 m/s

The sign minus means that vy change direction

Finally the horizontal distance is:

x = vₓ * t

x = 30 * 13.60 m

x = 408 m

5 0

2 years ago

A 70 Newton dog ran across the yard. What do we know about the dog?

Amiraneli [1.4K]

The dogs acceleration

5 0

3 years ago

The amount of gas that a helicopter uses is directly proportional to the number of hours spent flying. the helicopter flies for

igomit [66]

Answer:

The helicopter uses 35 gallons to fly for 5 hours.

Explanation:

The amount of gas that a helicopter uses for flying varies directly proportional to the number of hours spent flying.

g ∝ T

where g represents amount of gas and T time of flight.

Then,

$\therefore \frac{g_1}{g_2}=\frac{T_1}{T_2}$

The helicopter files 4 hours and uses 28 gallons of fuel.

Here, g₁= 28 gallons, T₁=4 hours

g₂=?, T₂=5 hours.

$\therefore \frac{g_1}{g_2}=\frac{T_1}{T_2}$

$\Rightarrow \frac{28}{g_2}=\frac{4}{5}$

⇒28×5= g₂×4

⇒ g₂×4=28×5

$\Rightarrow g_2=\frac{28\times 5}{4}$

$\Rightarrow g_2=35$ gallons

The helicopter uses 35 gallons to fly for 5 hours.

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3 years ago

Select the correct answer.

VLD [36.1K]

Answer:O – H

Explanation:

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3 years ago

PLS SHOW WORK !!!!!!! ASAP

Lynna [10]

Answer:

1- For the track B. The potential energy is the same for the two cars, but because of the slope of the track, the car B earn kinetic energy faster. The gravitation acceleration of the cars will be g•sinθ, and the angle of the track B will have a bigger value for sinθ

2- The conservation of energy applies because the roller coaster is a closed track. When a car climb the track, it earn GPE, which is given by mgh, when it get down in the track, it transform GPE in KE, which is given in 1/2mv².

Position of car (m) GPE KE GPE + KE

top (30m) 60000 0 60000

bottom (0m) 0 60000 60000

halfway down (15m) 30000 30000 60000

three-quarters way down 15000 45000 60000

4 0

3 years ago