Answer:
66.8°C
Explanation:
dQ = m*cp*dT where:
m = mass of block
cp = specific heat of iron
dT = temperature change
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dQ = 3.5 10^4 J
cp = 0.45 Kj / Kg = 450 J / Kg
3.5 10^4 = 2.3 * 450 * dt-----dt = 35000 / 450 * 2.3 = 33.8 °
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Final temperature = 33 + 33.8 = 66.8 °C
The answer is C, an educated guess
<h2>
Answer:</h2>
(a) 6.95 x 10⁻⁸ C
(b) 6.25N/C
<h2>
Explanation:</h2>
The electric field (E) on a point charge, Q, is given by;
E = k x Q / r² ---------------(i)
Where;
k = constant = 8.99 x 10⁹ N m²/C²
r = distance of the charge from a reference point.
Given from the question;
E = 10000N/C
r = 0.250m
Substitute these values into equation(i) as follows;
10000 = 8.99 x 10⁹ x Q / (0.25)²
10000 = 8.99 x 10⁹ x Q / (0.0625)
10000 = 143.84 x 10⁹ x Q
Solve for Q;
Q = 10000/(143.84 x 10⁹)
Q = 0.00695 x 10⁻⁵C
Q = 6.95 x 10⁻⁸ C
The magnitude of the charge is 6.95 x 10⁻⁸ C
(b) To get how large the field (E) will be at r = 10.0m, substitute these values including Q = 6.95 x 10⁻⁸ C into equation (i) as follows;
E = k x Q / r²
E = 8.99 x 10⁹ x 6.95 x 10⁻⁸ / 10²
E = 8.99 x 10⁹ x 6.95 x 10⁻⁸ / 100
E = 6.25N/C
Therefore, at 10.0m, the electric field will be just 6.25N/C
Answer:
Thumb
Explanation:
The direction of the magnetic field can be determined by using the right-hand rule. According to this rule, hold a current carrying wire in your right hand such that the thumb of the right-hand point in the direction of electric current. The curled finger gives the direction of the magnetic field.
Hence, the thumb shows the electric current.
Answer:
W = 20 J
Explanation:
Given that,
The mass of a loaded sack, m = 1000 g = 1 kg
It falls down from the floor of a lorry 200 cm high, h = 2 m
We need to find the work done by the gravity. The work done by an object under the action of gravity is given by :
W = mgh
Substitute all the values,
W = 1 × 10 × 2
= 20 J
Hence, the required work done by gravity is equal to 20 J.
