Answer:
(a) 37.5 kg
(b) 4
Explanation:
Force, F = 150 N
kinetic friction coefficient = 0.15
(a) acceleration, a = 2.53 m/s^2
According to the newton's second law
Net force = mass x acceleration
F - friction force = m a
150 - 0.15 x m g = m a
150 = m (2.53 + 0.15 x 9.8)
m = 37.5 kg
(b) As the block moves with the constant speed so the applied force becomes the friction force.

Alessandro Volta's battery was a simple and reliable source of electric current, which allowed scientists to study electricity better than they could with previous sources, such as the Leyden jar, and allowed the development of new technology powered by electricity.
Answer:
The ball takes 5s to reach the ground
Explanation:
in order to solve this problem we use the kinematics equation with gravity as acceleration:

we replace the values

We solve this quadratic equation:
t=5s
t=-6s (this solution has not physical sense)
Answer:
Final velocity of NFL line backer is 16.67 m/s.
Explanation:
From the question, we have following data about the NFL line backer:
Initial Speed of line backer = Vi = 0 m/s (Since, he starts from rest)
Distance covered by NFL line backer = s = 100 m
Time taken by the NFL line backer to complete 100 m sprint = t = 12 s
Acceleration of NFL line backer during sprint = a
Final Velocity of NFL line backer = Vf = ?
First we need to find the acceleration of the NFL line backer. For that purpose we will use 2nd equation of motion:
s = (Vi)(t) + (0.5)at²
using values:
100 m = (0 m/s)(12 s) + (0.5)(a)(12 s)²
100 m/72 s² = a
a = 1.39 m/s²
Now, we use 1st equation of motion to find Vf:
Vf = Vi + at
Vf = 0 m/s + (1.39 m/s²)(12 s)
<u>Vf = 16.67 m/s</u>
<h2>Answer : </h2>
Newton's Third law of motion states :
" Every action has an equal and opposite reaction "
i.e If a force is applied by an object A on another object B then that object B also exerts a foce on object A, that is of same magnitude and opposite direction to the force applied by object A.
Ex - A book on a table exerts gravitational force on the table and table exerts back a normal force on the book.