Kjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj
Force = mass x acceleration
Mass is given to be 250kg
Acceleration is given to be 5m/s^2
Force = 250kg x 5m/s^2 = 1,250 kgm/s^2 = 1,250 Newtons
Answer:
1.a) 1 kJ
1.b) 4 kJ
ratio 1:4
1.c) 4 times as before
2.a) 3.33 m/s2
Explanation:
1.a) bicycle's velocity =Displacement/time
=100/20 m/s
=5 m/s
bicycler's KE =1/2 *mass*(velocity)^2
=1/2*80*5^2
=1000 J = 1 kJ
1.b) bicycle's new velocity =200/20 m/s
=10 m/s
bicycler's new KE =1/2*80*10^2
=4000 J = 4 kJ
Ratio= KE 1 :KE new
= 1 :4
1.c) when bicycler's speed was doubled it increased the KE by 4 times (2^2). because In KE we consider the square of the speed , so the factor we increase the speed , the KE will get increased with the square value of it
ex : speed is triple the prior value , then the KE is as 3^2 times as before. that is 9 times
2.a) car acceleration = (20-0)/6 m/s2
= 3.33 m/s2
The reason why Kim's hair rises and sticks out is due to electrostatic attraction.
<h3>What is charging by friction?</h3>
We know that one of the ways in which a body is able to acquire static charges is by friction. When a body is rubbed against another, there could be loss or gain of charges leaving a net charge on each body.
The process that occurs when some of Kim's hair rises and sticks out toward the balloon, even though the balloon hasn't touched her hair is electrostatic attraction.
Learn more about charging by friction:brainly.com/question/9201910
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