Answer:
Explanation:
the force that you applied caused the notebook to move.
the force applied on the notebook by the table causes it to stop moving.
this is because after sometime the book uses up the force and later the force you applied is less than that of the force by the table.
Answer:
156.26N
Explanation:
The data needed are incomplete. Let the acceleration of the body be 3.5m/s²
Other given parameters
Mass = 1.35×10^1 = 13.5kg
coefficient of friction between the tires and the road = 0.850
Acceleration due to gravity = 9.8m/s²
According to Newton's second law:
Fnet = ma
Fnet = Fapp - Ff
Fapp is the applied force
Ff is the frictional force = umg
The equation becomes:
Fapp - Ff = ma
Fapp-umg = ma
Fapp - 0.85(13.5)(9.8) = 13.5(3.5)
Fapp - 109.0125 = 47.25
Fapp = 47.25+109.0125
Fapp = 156.2625N
Hence the applied force that caused the acceleration is 156.26N
Note that the acceleration of the car was assumed. Any value of acceleration can be used for the calculation.
For this case we first think that the skateboard and the child are one body.
We have then:
1 = jug
2 = skateboard + boy
By conservation of the linear amount of movement:
M1V1i + M2V2i = M1V1f + M2V2f
Initial rest:
v1i = v2i = 0
0 = M1V1f + M2V2f
Substituting values
0 = (7.8) (3.2) + (M2) (- 0.65)
0 = 24.96 + M2 (-0.65)
-24.96 = (-0.65) M2
M2 = (-24.96) / (- 0.65) = 38.4 kg
Then, the child's mass is:
M2 = Mskateboard + Mb
Clearing:
Mb = M2-Mskateboard
Mb = 38.4 - 1.9
Mb = 36.5 Kg
answer:
the boy's mass is 36.5 Kg
