The spoon to transfer 40 J of energy to your hand is descibed as follows
<u>Explanation:</u>
Given area of cross section of copper spoon is A = 20mm into 1.5 mm
temperature difference is DT = (100 minus 35) = 65 0C
length of the spoon is l = 18 cm,
amount of heat should be transfer Q = 40 J
coefficient of thermal conductivity of copper k = 400 W by mk
we know that the thermal conductivity is Q by t = k into A into DT by l
t = Q into l by k into A into DT
t = (40 into 0.18) by
t = 9.23 s
Answer:
d). The value of y should be -32m
Vx=0.92 m/s
Explanation:
Using equation of motion uniform to y motion
So to find t that is the same time for all the motion
The value of Xf=-3.2m because the g is negative from the axis
Now in the axis 'x' to find Vx
Answer:
1) The person whose velocity changes more is Marner
2) The change in velocity of Marner is more than the change in velocity of Chara because Chara has more mass than Marner
Explanation:
The given information are
The mass of Mitch Marner = 80 kg
The mass of Zdano Chara = 116 kg
Marner's skating speed before the collision = 10 m/s
From the principle of conservation of linear momentum, we have;
Total initial momentum before the collision = Total final momentum after the collision
m₁×u₁ + m₂×u₂ = m₁×v₁ + m₂×v₂
Where;
m₁ = The mass of Mitch Marner = 80 kg
m₂ = The mass of Zdano Chara = 116 kg
u₁ = The initial velocity of Mitch Marner = 10 m/s
u₂ = The initial velocity of Zdano Chara = 0 m/s
v₁ = The final velocity of Mitch Marner
v₂ = The final velocity of Zdano Chara
Given that the collision is head on, they can be assumed to have an equal instantaneous velocity immediately after collision, therefore;
v₁ = v₂ = v
We have;
m₁×u₁ + m₂×u₂ = (m₁ + m₂) × v₂
By substituting the values, we have;
80 × 10 + 110 × 0 = (80 + 110) × v = 190 × v
Which gives;
80 × 10 + 110 × 0 = 190 × v
800 = 190 × v
v = 800/190 = 80/19 =
Therefore the instantaneous final velocity of both Marner and Chara is
The change in velocity of Marner =
The change in velocity of Chara =
Therefore;
1) The person whose velocity changes more is Marner
2) The reason is because the ratio of her mass to the combined mass of both of them is less than the ratio of the Chara;s mass to the combined mass of them both
Which means that the change in velocity of Marner is more than the change in velocity of Chara because Chara has more mass than Marner.