The reason because the other ones deals with radiation. Only C.) is the right answer because the feet is touching the hot pavement which is conduction.

3 0

4 years ago

An object in projectile motion will follow wich path

seraphim [82]

It will tend to follow a trajectory path. When a projectile is being flung or flown away by a certain type of force, the trajectory is what it follows through the means of both force and function of time itself. It's also called as flight path.

6 0

4 years ago

A block of mass m = 2.5 kg is attached to a spring with spring constant k = 730 N/m. It is initially at rest on an inclined plan

Alona [7]

Answer:

A) Em = 4.41 J

B) L = 0.33m

Explanation:

A) The total mechanical energy of the block is the elastic potential energy due to the compressed spring. The gravitational energy is zero. Then you have:

$E_m=\frac{1}{2}k(\Delta x)^2$

k: constant's spring = 730 N/m

Δx: distance of the compression = 0.11m

You replace the values of k and Δx:

$E_m=\frac{1}{2}(730N/m)(0.11m)^2=4.41\ J$

B) To find the distance L traveled by the block you take into account that the total mechanical energy of the block is countered by the work done by the friction force, and also by the work done by the gravitational energy.

Then, you have:

$E_m-W_f-W_g=0\\\\W_f=(\mu Mg cos\theta)L\\\\W_g=(Mgsin\theta)L$

μ: coefficient of kinetic friction = 0.19

g: gravitational acceleration = 9.8m/s^2

M: mass of the block = 2.5kg

θ: angle of the inclined plane = 21°

You replace the values of all parameters:

$E_m-W_f-W_g=0\\\\4.41-(0.19)(2.5kg)(9.8m/s^2)(cos21\°)L-(2.5kg)(9.8m/s^2)(sin21\°)L=0\\\\4.41-4.34L-8.78L=0\\\\4.41-13.12L=0\\\\L=0.33m$

hence, the distance L in which the block stops is 0.33m

5 0

3 years ago