If the object is moving in a straight line with constant speed,
that's a description of " acceleration = zero ".
Zero acceleration means zero net force on the object.
NO net force is 'required' to keep an object moving in a straight line
at constant speed. In fact, if there IS any net force on the object,
then either its speed or its direction MUST change ... there's no way
to avoid it.
None of this depends on the object's mass, or on the speed or direction
of its motion.
(a) The ball's height <em>y</em> at time <em>t</em> is given by
<em>y</em> = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity. Solve <em>y</em> = 0 for <em>t</em> :
0 = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
0 = <em>t</em> ((20 m/s) sin(40º) - 1/2 <em>g t</em> )
<em>t</em> = 0 or (20 m/s) sin(40º) - 1/2 <em>g t</em> = 0
The first time refers to where the ball is initially launched, so we omit that solution.
(20 m/s) sin(40º) = 1/2 <em>g t</em>
<em>t</em> = (40 m/s) sin(40º) / <em>g</em>
<em>t</em> ≈ 2.6 s
(b) At its maximum height, the ball has zero vertical velocity. In the vertical direction, the ball is in free fall and only subject to the downward acceleration <em>g</em>. So
0² - ((20 m/s) sin(40º))² = 2 (-<em>g</em>) <em>y</em>
where <em>y</em> in this equation refers to the maximum height of the ball. Solve for <em>y</em> :
<em>y</em> = ((20 m/s) sin(40º))² / (2<em>g</em>)
<em>y</em> ≈ 8.4 m
Answer:
The frictional torque is
Explanation:
From the question we are told that
The mass attached to one end the string is
The mass attached to the other end of the string is
The radius of the disk is
At equilibrium the tension on the string due to the first mass is mathematically represented as
substituting values
At equilibrium the tension on the string due to the mass is mathematically represented as
The frictional torque that must be exerted is mathematically represented as
substituting values
Answer:
= 0.5 m/s²
Explanation:
- According to Newton's second law of motion, the resultant force is directly proportion to the rate of change of linear momentum.
Therefore;<em> F = ma , where F is the Force, m is the mass and a is the acceleration.</em>
<em>Thus; a = F/m</em>
<em>but; F = 5 N, and m = 10 kg</em>
<em> a = 5 /10</em>
<u>= 0.5 m/s²</u>
Answer:
Nucleus And electron cloud
Explanation:
Hope this helps