When the velocity increases, then the acceleration will be positive and when the velocity decrease then the acceleration will be negative.
During the first hour, the velocity was 70 mph and during the seconds hour the velocity was 60 mph. Hence, the velocity decrease in the seconds hour. So, the acceleration will be negative during the second hour.
Now, during the third hour the velocity increases as it is 80 mph. Hence, the acceleration will be positive during the third hour.
Work = Force x Distance
47.2J = 23.3N x d
d = 47.2/23.3
d = 2.0258 m
hope this helps :P
Answer:
None
Explanation:
Force, F is given by ma where m is the mass of an object and a is acceleration
Acceleration is the rate of change in velocity per unit time. Since skaters with mass of 75 kg and 50 kg are moving at a constant speed, there is no acceleration hence F=50*0=0 and F=75*0=0
For skater of 45 kg, he is at rest to mean the initial and final velocitu of the skater is zero hence no acceleration, the force will be 45*0=0
Therefore, none of the skaters will experience a greater net force.
Answer:
Explanation:
It's equal to change of momentum in contact
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