Two people walking on a sidewalk have the following

Sedaia [141]

C. A survey is asking people what they think is the answer.

5 0

4 years ago

If he leaves the ramp with a speed of 31.0 m/s and has a speed of 29.5 m/s at the top of his trajectory, determine his maximum h

raketka [301]

Answer:

The maximum height reached is 4.63 m.

Explanation:

Given:

Initial speed of the man (u) = 31.0 m/s

Speed at the top of trajectory ( $u_x$ ) = 29.5 m/s

Acceleration due to gravity (g) = 9.8 m/s²

When the man reaches the top of the trajectory, the vertical component of velocity becomes zero and hence only horizontal component of velocity acts on him.

Also, since there is no net force acting in the horizontal direction, the acceleration is zero in the horizontal direction from Newton's second law. Thus, the horizontal component of velocity always remains the same.

So, speed at the top of trajectory is nothing but the horizontal component of initial velocity.

Now, initial velocity can be rewritten in terms of its components as:

$u^2=u_x^2+u_y^2$

Where, $u_x\ and\ u_y$ are the initial horizontal and vertical velocities of the man.

Now, plug in the given values and simplify. This gives,

$(31.0)^2=(29.5)^2+u_y^2\\\\961=870.25+u_y^2\\\\u_y^2=961-870.25\\\\u_y^2=90.75\ m^2/s^2--------1$

Now, we know that, for a projectile motion, the maximum height is given as:

$H=\frac{u_y^2}{2g}$

Plug in the value from equation (1) and 9.8 for 'g' to solve for 'H'. This gives,

$H=\frac{90.75}{2\times 9.8}\\\\H=4.63\ m$

Therefore, the maximum height reached is 4.63 m.

3 0

4 years ago

Two trains move towards each other on a straight track/railroad. The left train has a constant speed of 29ms, the right train ha

laiz [17]

Answer:

The left train travels 2378 m until it reaches the meeting point.

Explanation:

The equation for the position of the trains is the following:

x = x0 + v · t

Where:

x = position at time t

x0 = initial position

v = velocity

t = time

If we place the origin of the frame of reference at the initial position of the left train, the right train will be at an initial position of 4744. 6 m relative to the left train. The velocity of the right train will be negative because it will be heading towards the origin.

At the meeting point, the position of both trains is the same:

x left train = x right train

x0₁ + v₁ ·t = x0₂ + v₂ · t

0m + 29 m/s · t = 4744.6 m - 29 m/s · t

58 m/s · t = 4744.6 m

t = 4744.6 m / 58 /s

t = 82 s

The position of the left train at that time will be:

x = x0 + v · t

x = 0 m + 29 m/s · 82 s

x = 2378 m

The left train travels 2378 m until it reaches the meeting point.

7 0

3 years ago

The principle of conservation of momentum is most similar to which of newton's laws of motion?

Effectus [21]

Newton’s Thrid Law, which states that for every reaction there is an opposite reaction.

6 0

3 years ago

Problem 20.75 A thin rectangular coil 2 cm by 9 cm has 44 turns of copper wire. It is made to rotate with angular frequency 110

NeTakaya

Answer:

(a) 16.5528 V

(b) 827.64 W

Explanation:

(a)

The formula for maximum emf produced in a coil is given as

E₀ = BANω.................. Equation 1

Where E₀ = maximum emf produced in the coil, B = magnetic Field, A = Area of the rectangular coil, N = number of turns, ω = angular velocity.

Given: B = 1.9 T, N = 44 turns, ω = 110 rad/s, A = 2×9 = 18 cm² = 18/10000 = 0.0018 m²

Substitute into equation 1

E₀ = 1.9(44)(110)(0.0018)

E₀ = 16.5528 V

(b)

Maximum power

P₀ = E₀²/R...................... Equation 2

Where R = Resistance.

Given: R = 50 ohms, E₀ = 16.5528 V

Substitute into equation 2

P₀ = 50(16.5528)

P₀ = 827.64 W

8 0

3 years ago