<h3>
Answer: 130 newtons</h3>
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Explanation:
We'll need the acceleration first.
- The initial speed (let's call that Vi) is 8.0 m/s
- The final speed (Vf) is 0 m/s since Sam comes to a complete stop at the end.
- This happens over a duration of t = 4.0 seconds
The acceleration is equal to the change in speed over change in time
a = acceleration
a = (change in speed)/(change in time)
a = (Vf - Vi)/(4 seconds)
a = (0 - 8.0)/4
a = -8/4
a = -2
The acceleration is -2 m/s^2, meaning that Sam slows down by 2 m/s every second. Negative accelerations are often associated with slowing down. The term "deceleration" can be used here.
Here's a further break down of Sam's speeds at the four points of interest
- At 0 seconds, he's going 8 m/s
- At the 1 second mark, he's slowing down to 8-2 = 6 m/s
- At the 2 second mark, he's now at 6-2 = 4 m/s
- At the 3 second mark, he's at 4-2 = 2 m/s
- Finally, at the 4 second mark, he's at 2-2 = 0 m/s
Next, we'll apply Newton's Second Law of motion
F = m*a
where,
- F = force applied
- m = mass
- a = acceleration
We just found the acceleration, and the mass is fairly easy as all we need to do is add Sam's mass with the sled's mass to get 60+5.0 = 65 kg
So the force applied must be:
F = m*a
F = 65*(-2)
F = -130 newtons
This force is negative to indicate it's pushing against the sled's momentum to slow Sam down.
The magnitude of this force is |F| = |-130| = 130 newtons
When the applied force increases to 5 N, the magnitude of the block's acceleration is 1.7 m/s².
<h3>
Frictional force between the block and the horizontal surface</h3>
The frictional force between the block and the horizontal surface is determined by applying Newton's law;
∑F = ma
F - Ff = ma
Ff = F - ma
Ff = 4 - 2(1.2)
Ff = 4 - 2.4
Ff = 1.6 N
When the applied force increases to 5 N, the magnitude of the block's acceleration is calculated as follows;
F - Ff = ma
5 - 1.6 = 2a
3.4 = 2a
a = 3.4/2
a = 1.7 m/s²
Thus, when the applied force increases to 5 N, the magnitude of the block's acceleration is 1.7 m/s².
Learn more about frictional force here: brainly.com/question/4618599
Answer:
1793.7m
Explanation:
From the principle of conservation of energy; the kinetic energy substended by the object equals the potential energy sustain by the object when it gets to its maximum position.
Now the kinetic energy; is
K.E = 1/2 × m × v2
Where m is mass
v is velocity
Hence.
K.E = 1/2 × 2.25 × (187.5)^2
Now this should be same with the potential energy which is given as;
P.E = m× g× h
Where m is mass of object
g is acceleration of free fall due to gravity = 9.8m/S2
h is maximum height substain by the object.
Hence P.E = 2.25 × 9.8 × h
From the foregoing analysis of energy conversation it implies;
1/2 × 2.25 × (187.5)^2 =2.25 × 9.8 × h
=> 1/2 × (187.5)^2 = 9.8 × h
=>1/2 × (187.5)^2 / 9.8 = h
=> 1793.69m = h
h= 1793.69m
h =1793.7m to 1 decimal place
The magnitude of the sum of the frictional forces acting on the bike and its rider is 400N.
<h3>What is friction force?</h3>
The friction force is the opposing force which acts on the object which is in relative motion.
The driving force is equal and opposite to the friction force acting between road and bicycle.
Friction force = 400N
The friction force between rider and bike is zero.
So the magnitude of sum of friction force = 400N +0 = 400N
Thus, the magnitude of the sum of the frictional forces acting on the bike and its rider.
Learn more about friction force.
brainly.com/question/1714663
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The tape is charged by friction and her hand has an induced opposite charge. They therefore attract.
