The answer to question one is A.
The answer to question two is A.
The answer to question three is D.
Answer:
m=0.5kg
h = 180 cm =1.8 mh=180cm=1.8m
Initial potential energy of the object is:
E_p=m*g*hE
p
=m∗g∗h
Kinetic energy at the surface:
E_k=\frac{mv^2}{2}E
k
=
2
mv
2
According to the law of conservation of energy (assuming no air resistance):
E_p = E_kE
p
=E
k
mgh=\frac{mv^2}{2}mgh=
2
mv
2
Solving for v:
v=\sqrt{2gh}v=
2gh
p=mvp=mv
So,
p= m*v = m\sqrt{2gh}p=m∗v=m
2gh
Calculating:
p= 0.5\sqrt{2*9.8*1.8}\approx 2.97 \frac{kg*m}{s}p=0.5
2∗9.8∗1.8
≈2.97
s
kg∗m
Answer:
p \approx 2.97 \frac{kg*m}{s}p≈2.97
s
kg∗m
The best and most correct answer among the choices provided by your question is the second choice or letter b.
Ex is negative from x = -2 to x = 0, and positive from x = 0 to x = 2 <span>correctly describes the orientation of the x-component of the electric field along the x-axis.</span>
I hope my answer has come to your help. Thank you for posting your question here in Brainly. We hope to answer more of your questions and inquiries soon. Have a nice day ahead!
Answer:
Value of acceleration in each case is ![7.52\ m/s^2 \ and \ 7.14\ m/s^2.](https://tex.z-dn.net/?f=7.52%5C%20m%2Fs%5E2%20%5C%20and%20%5C%207.14%5C%20m%2Fs%5E2.)
Explanation:
According to newton's law :
...equation 1.
In the given case,
Force by both the children - Friction force .
![F_{net} = (75+95)-12=158\ N.](https://tex.z-dn.net/?f=F_%7Bnet%7D%20%3D%20%2875%2B95%29-12%3D158%5C%20N.)
Putting value of F in equation 1.
![a=\dfrac{F_{net}}{m}=\dfrac{158}{21}=7.52\ m/s^2.](https://tex.z-dn.net/?f=a%3D%5Cdfrac%7BF_%7Bnet%7D%7D%7Bm%7D%3D%5Cdfrac%7B158%7D%7B21%7D%3D7.52%5C%20m%2Fs%5E2.)
Now, if friction force = 20 N.
Therefore, ![F_{net}=(75+95)-20=150\ N.](https://tex.z-dn.net/?f=F_%7Bnet%7D%3D%2875%2B95%29-20%3D150%5C%20N.)
Putting value of F and a in equation 1.
![a=\dfrac{F_{net}}{m}=\dfrac{150}{21}=7.14\ m/s^2.](https://tex.z-dn.net/?f=a%3D%5Cdfrac%7BF_%7Bnet%7D%7D%7Bm%7D%3D%5Cdfrac%7B150%7D%7B21%7D%3D7.14%5C%20m%2Fs%5E2.)
Hence , this is the required solution.