(a) The minimum force F he must exert to get the block moving is 38.9 N.
(b) The acceleration of the block is 0.79 m/s².
<h3>
Minimum force to be applied </h3>
The minimum force F he must exert to get the block moving is calculated as follows;
Fcosθ = μ(s)Fₙ
Fcosθ = μ(s)mg
where;
- μ(s) is coefficient of static friction
- m is mass of the block
- g is acceleration due to gravity
F = [0.1(36)(9.8)] / [(cos(25)]
F = 38.9 N
<h3>Acceleration of the block</h3>
F(net) = 38.9 - (0.03 x 36 x 9.8) = 28.32
a = F(net)/m
a = 28.32/36
a = 0.79 m/s²
Thus, the minimum force F he must exert to get the block moving is 38.9 N.
The acceleration of the block is 0.79 m/s².
Learn more about minimum force here: brainly.com/question/14353320
#SPJ1
Answer:
A. That enough light of any frequency would cause electrons to flow.
Explanation:
A P E X
Answer:
a) ![v=7.32m/s](https://tex.z-dn.net/?f=v%3D7.32m%2Fs)
b)
º
c) ![ΔK=-1094.62J](https://tex.z-dn.net/?f=%CE%94K%3D-1094.62J)
Explanation:
From the exercise we know that the collision between Daniel and Rebecca is elastic which means they do not stick together
So, If we analyze the collision we got
![p_{1x}=p_{2x}](https://tex.z-dn.net/?f=p_%7B1x%7D%3Dp_%7B2x%7D)
To simplify the problem, lets name D for Daniel and R for Rebecca
a) ![p_{D1x}+p_{R1x}=p_{D2x}+p_{R2x}](https://tex.z-dn.net/?f=p_%7BD1x%7D%2Bp_%7BR1x%7D%3Dp_%7BD2x%7D%2Bp_%7BR2x%7D)
Since Daniel's initial velocity is 0
![m_{R}v_{Rx}=m_{D}v_{D2x}+m_{R}v_{R2x}](https://tex.z-dn.net/?f=m_%7BR%7Dv_%7BRx%7D%3Dm_%7BD%7Dv_%7BD2x%7D%2Bm_%7BR%7Dv_%7BR2x%7D)
![v_{D2x}=\frac{m_{R}*v_{R1x}-m_{R}*v_{R2x}}{m_{D}}](https://tex.z-dn.net/?f=v_%7BD2x%7D%3D%5Cfrac%7Bm_%7BR%7D%2Av_%7BR1x%7D-m_%7BR%7D%2Av_%7BR2x%7D%7D%7Bm_%7BD%7D%7D)
![v_{D2x}=\frac{(45kg)(14m/s)-(45kg)(8cos(55.1)m/s)}{(70kg)}=6m/s](https://tex.z-dn.net/?f=v_%7BD2x%7D%3D%5Cfrac%7B%2845kg%29%2814m%2Fs%29-%2845kg%29%288cos%2855.1%29m%2Fs%29%7D%7B%2870kg%29%7D%3D6m%2Fs)
Now, lets analyze the movement in the vertical direction
![p_{1y}=p_{2y}](https://tex.z-dn.net/?f=p_%7B1y%7D%3Dp_%7B2y%7D)
Since ![p_{1y}=0](https://tex.z-dn.net/?f=p_%7B1y%7D%3D0)
![0=m_{D}v_{D2y}+m_{R}v_{R2y}](https://tex.z-dn.net/?f=0%3Dm_%7BD%7Dv_%7BD2y%7D%2Bm_%7BR%7Dv_%7BR2y%7D)
![v_{D2y}=-\frac{m_{R}v_{2Ry}}{m_{D}}=-\frac{(45kg)(8sin(55.1)m/s)}{(70kg)}=-4.21m/s](https://tex.z-dn.net/?f=v_%7BD2y%7D%3D-%5Cfrac%7Bm_%7BR%7Dv_%7B2Ry%7D%7D%7Bm_%7BD%7D%7D%3D-%5Cfrac%7B%2845kg%29%288sin%2855.1%29m%2Fs%29%7D%7B%2870kg%29%7D%3D-4.21m%2Fs)
Now, we can find the magnitude of Daniel's velocity after de collision
![v_{D}=\sqrt{(6m/s)^2+(-4.21m/s)^2}=7.32m/s](https://tex.z-dn.net/?f=v_%7BD%7D%3D%5Csqrt%7B%286m%2Fs%29%5E2%2B%28-4.21m%2Fs%29%5E2%7D%3D7.32m%2Fs)
b) To know whats the direction of Daniel's velocity we need to solve the arctan of the angle
º
c) The change in the total kinetic energy is:
ΔK=![K_{2}-K_{1}](https://tex.z-dn.net/?f=K_%7B2%7D-K_%7B1%7D)
ΔK=![\frac{1}{2}[(45kg)(8m/s)^2+(70kg)(7.32m/s)^2-(45kg)(14m/s)^2]=-1094.62J](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%5B%2845kg%29%288m%2Fs%29%5E2%2B%2870kg%29%287.32m%2Fs%29%5E2-%2845kg%29%2814m%2Fs%29%5E2%5D%3D-1094.62J)
That means that the kinetic energy decreases
<span>Refrigerator - Contains Induction motor in compressor.
</span><span>Toys - DC motors.</span>