Answer:
Choice a. 
, assuming that the skating rink is level.
Explanation:
<h3>Net force in the horizontal direction</h3>
There are two horizontal forces acting on the boy:
- The pull of his friend, and
- Frictions.
The boy should be moving in the direction of the pull of his friend. The frictions on this boy should oppose that motion. Therefore, the frictions on the boy would be in the opposite direction of the pull of his friend.
The net force in the horizontal direction should then be the difference between the pull of the friend, and the friction on this boy.
.
<h3>Net force in the vertical direction</h3>
The net force on this boy should be zero in the vertical direction. Consider Newton's Second Law of motion. The net force on an object is proportional to its acceleration. In this question, the net force on this boy in the vertical direction should be proportional to the vertical acceleration of this boy.
However, because (by assumption) the ice rink is level, the boy has no motion in the vertical direction. His vertical acceleration will be zero. As a result, the net force on him should also be zero in the vertical direction.
<h3>Net force</h3>
Therefore, the (combined) net force on this boy would be:
.
Answer:
A The shorter the wavelength the higher the frequency the longer the lower, hope this helps, thanks.
<span>The earth as a whole rotates with a fixed angular velocity. Therefore, you
need to be at the rotation axis to have the smallest tangential speed. This
would be at the north or south pole.</span>
Answer:
- 8.33 x 10⁻³ rad /s ( anticlockwise)
Explanation:
The rotational movement of beetle and turntable is caused by torque generated by internal forces , we can apply conservation of angular momentum.
That is ,
I₁ ω₁ = I₂ω₂ , ω₁ and ω₂ are angular velocity of beetle and turntable respectively.
ω₁ + ω₂ = .05 radian /s ( given )
Momentum of inertia of beetle I₁ = mass x (distance from axis)²
= 15 x 10⁻³ x R² ( R is radius of the turntable )
Momentum of inertia of turntable I₂ =1/2 mass x (distance from axis)²
= 75/2 x 10⁻³ x R² ( R is radius of the turntable )
I₁ ω₁ = I₂ω₂ ,
15 x 10⁻³ x R² x ( .05 - ω₂ ) = 75/2 x 10⁻³ x R² ω₂
15 x ( .05 - ω₂ ) = 75/2 x ω₂
.75 - 15ω₂ = 37.5ω₂
.75 = 52.5 ω₂
ω₂ = - 14.3 x 10⁻³ rad /s ( anticlockwise)
Answer:
13.33 K
Explanation:
Given that,
Heat absorbed, Q = 30 J
Mass of nail, m = 5 g = 0.005 kg
The specific heat capacity of the nail is 450 J/kg-°C.
We need to find the increase in the temperature during the process. The heat absorbed in a process is as follows:
So, the increase in temperature is 13.33 K.
