Answer:
Kr
Explanation:
the element that is in group 18 is noble gasses. the elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), radon (Rn), and oganesson (Og).
Answer:
D. Ted expanded more power.
Explanation:
Given the following data;
For Ted.
Force = 10N
Height = 1.5m
Time = 1 seconds
To find Ted's power;
Power = workdone/time
But workdone = force * distance
Workdone = 10 * 1.5
Workdone = 15 Nm
Power = 15/1
Power = 15 Watts.
For Johnny.
Force = 10N
Height = 1.5m
Time = 2 seconds
To find Ted's power;
Power = workdone/time
But workdone = force * distance
Workdone = 10 * 1.5
Workdone = 15 Nm
Power = 15/2
Power = 7.5 Watts
Therefore, from the calculations we can deduce and conclude that Ted expanded more power.
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
