Answer:
C) When wind direction or wind speed changes with altitude :)
Explanation:
Answer:
Approximately 
(assuming that 
.)
Explanation:
Let 
denote the force that this spring exerts on the object. Let 
denote the displacement of this spring from the equilibrium position.
By Hooke's Law, the spring constant 
of this spring would ensure that 
.
Note that the mass of the object attached to this spring is 
. Thus, the weight of this object would be 
.
Assuming that this object is not moving, the spring would need to exert an upward force of the same magnitude on the object. Thus, 
.
The spring in this question was stretched downward from its equilibrium by:
.
(Note that is negative since this displacement points downwards.)
Rearrange Hooke's Law to find in terms of and :
.
Answer:
Explanation:
Let the bigger crate be in touch with the ground which is friction less. In the first case both m₁ and m₂ will move with common acceleration because m₁ is not sliding over m₂.
1 ) Common acceleration a = force / total mass
= 234 / ( 25 +91 )
= 2.017 m s⁻².
2 ) Force on m₁ accelerating it , which is nothing but friction force on it by m₂
= mass x acceleration
= 25 x 2.017
= 50.425 N
The same force will be applied by m₁ on m₂ as friction force which will act in opposite direction.
3 ) Maximum friction force that is possible between m₁ and m₂
= μ_s m₁g
= .79 x 25 x 9.8
= 193.55 N
Acceleration of m₁
= 193 .55 / 25
= 7.742 m s⁻²
This is the common acceleration in case of maximum tension required
So tension in rope
= ( 25 +91 ) x 7.742
= 898 N
4 ) In case of upper crate sliding on m₂ , maximum friction force on m₁
= μ_k m₁g
= .62 x 25 x 9.8
= 151.9 N
Acceleration of m₁
= 151.9 / 25
= 6.076 m s⁻².
Answer:
58.8 N
Explanation:
The normal force is calculated as equal to the perpendicular component of the gravitational force.
Thus; N = mg
We are given m = 6 kg
Thus;
N = 6 × 9.8
N = 58.8 N
Thus, magnitude of normal force on the rock = 58.8 N
Answer:
D
Explanation:
Scientists use significant figures to avoid claiming more accuracy in a calculation than they actually know.
