Which of the following defines heredity?

Timmy bikes to school 3 kilometers east and 2 kilometers south. What is Timmy's final displacement?

vovikov84 [41]

Answer:

3.6km South East

Explanation:

Displacement is the shortest distance between the starting point and the ending point and the direction it is displaced in. To calculate the displacement we can use the pythagoras theorem because the 3km East and the 2km south form the two shorter sides of a right angled triangle between the starting and ending points. So, the displacement is the length C of the triangle which we can calculate as follows:

Pythagoras Theorem:

a^2+b^2=c^2

(2)^2+(3)^2=c^(2)

4+9=c^2

Square root 13 = c

c=3.6km (1dp)

The total displacement is 3.6km and is in the approximate direction of South East (because he travelled east and south).

Hope this helped!

8 0

2 years ago

What temperature increase is necessary to increase the power radiated from an object by a factor of 8?

Aleks04 [339]

To solve this problem it is necessary to apply the concepts related to the Power defined from the Stefan-Boltzmann equations.

The power can be determined as:

$P = \sigma T^4$

Making the relationship for two states we have to

$\frac{P_1}{P_2} = \frac{T_1^4}{T_2^4}$

Since the final power is 8 times the initial power then

$P_2 = 8P_1$

Substituting,

$\frac{1}{8} = \frac{T_1^4}{T_2^4}$

$T_2 = T_1 8*(\frac{1}{4})$

$T_2 = 1,68T_1$

The temperature increase would then be subject to

$\Delta T = T_2-T_1$

$\Delta T = 1.68T_1 -T_1$

$\Delta T = 0.68T_1$

The correct option is D, about 68%

7 0

2 years ago

A basketball of mass 0.23kg is thrown horizontally against a rigid vertical wall with a velocity of 20m/s. It rebounds with a ve

Anna11 [10]

Answer:

$8.1\:\mathrm{Ns}$

Explanation:

The impulse-momentum theorem gives the impulse on an object to be equal to the change in momentum of that object. Since mass is maintained, the change in momentum of the basketball is:

$\Delta p = m\Delta v$ , where $m$ is the mass of the basketball and $\Delta v$ is the change in velocity.

Since the basketball is changing direction, its total change in velocity is:

$\Delta v = 20-(-15)=35\:\mathrm{m/s}$ .

Therefore, the basketball's change in momentum is:

$\Delta p = m\Delta v = 0.23\cdot 35= 8.05=8.1\:\mathrm{kg\cdot m/s}$ .

Thus, the impulse on the basketball is $\fbox{$8.1\:\mathrm{Ns}$}$ (two significant figures).

7 0

2 years ago

Bill steps off a 3.0-m-high diving board and drops to the water below. At the same time, Ted jumps upward with a speed of 4.2 m/

Pani-rosa [81]

Answer:

equation of motion for Bill is

$y(t) = 4.9t^2$

equation of motion for Ted is

$y(t) = 2 + (-4.2)(t) + 4.9t^2$

Explanation:

Taking downward position positive and upward position negative

g = 9.8 m/s^2

equation of motion for Bill is

$y(t) = y_0 +v_0 t +\frac{1}{2}gt^2$

$y(t) = 0 + 0(t) +\frac{1}{2}gt^2$

$y(t) = \frac{1}{2}\times (9.8t)^2$

$y(t) = 4.9t^2$

equation of motion for Ted is

$y_0 = 2m -1m = 2m$

$y_0 = -4.2 m/s$

$y(t) = y_0 +v_0 t +\frac{1}{2}gt^2$

$y(t) = 2 + (-4.2)(t) +\frac{1}{2}gt^2$

$y(t) = 2 + (-4.2)(t) +\frac{1}{2}\times (9.8t)^2$

$y(t) = 2 + (-4.2)(t) + 4.9t^2$

8 0

3 years ago

Read 2 more answers

A 50 kg crate is pulled across the ice by a rope that is angled at 30 degrees above the horizontal. If the tension in the rope i

denpristay [2]

Let:
Vx = the pulling component of force
Vy = the lifting component of force

Vy:
Sin(n°) = Vy/hypotenuse
hypotenuse * Sin(n°) = Vy
100N*sin(30°) = Vy
50N = Vy

Vx:
Cos(n°) = Vx/hypotenuse
Hypotenuse * cos(n°) = Vx
100N*cos(30°) =Vx
about 86.6N = Vx

4 0

3 years ago