Yes, Sliding friction opposes the movement of the book, slowing it down.sliding That's the 'kinetic' kind.. According to Newton's second law, F=ma. That is, the bear's acceleration should be proportional to the total force acting on the bear. As the bear's velocity is constant, its acceleration is zero. Therefore, the total Force acting on the bear is zero. Thus, the friction has to be equal in magnitude and opposite in direction to the bear's weight. As W=mg, we get that its weight is <span>9.8*400=3,920 Newton. Thus, the friction acting on the bear is 3,920 Newton</span>
Answer:
All these is caused by the repulsion force.
Explanation:
The electroscope produces a series of electric charges that produce a repulsion force when is putted in contact with a electric charged object.
As the physics law mentions, two different forces are repealed, the electrocospe is charged negatively and the object positively, causing a repulsion force that avoids that both objects touch the other.
Answer:
11 because the number of protons is the atomic humber
Explanation:
Answer:
.
Explanation:
Let 
denote the absolute temperature of this object.
Calculate the value of before and after heating:
.
.
By the Stefan-Boltzmann Law, the energy that this object emits (over all frequencies) would be proportional to 
.
Ratio between the absolute temperature of this object before and after heating:
.
Therefore, by the Stefan-Boltzmann Law, the ratio between the energy that this object emits before and after heating would be:
.
Answer:
x = 0.0734 m = 7.34 cm
Explanation:
First we shall calculate the area of the piston:
Now, we will calculate the force on the piston due to atmospheric pressure:
Now, for the compression of the spring we will use Hooke's Law as follows:
where,
k = spring constant = 3400 N/m
x = compression = ?
Therefore,
<u>x = 0.0734 m = 7.34 cm</u>
