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
Answer:
The magnification is -6.05.
Explanation:
Given that,
Focal length = 34 cm
Distance of the image =2.4 m = 240 cm
We need to calculate the distance of the object

Where, u = distance of the object
v = distance of the image
f = focal length
Put the value into the formula



The magnification is



Hence, The magnification is -6.05.
The heat energy transferred by the iron nail is 4680 J
Explanation:
The thermal energy transferred by a substance to another substance is given by the equation

where
m is the mass of the substance
C is its specific heat capacity
is its change in temperature
For the iron nail in this problem, we have:
m = 16 g


So, the amount of heat energy given off by the nail is

where the negative sign indicates that the heat is given off.
Learn more about specific heat capacity:
brainly.com/question/3032746
brainly.com/question/4759369
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Explanation:
When one coulomb charge passes through any cross section of the wire per second,the current passing is one ampere. Charge of electron ,e=1.6X10^-19C. n=1/(1.6X10^-19)=6.25X10^18.Sep 17, 2017