8 POINTS EASY MULTIPLE CHOICE, BRAINLIST FOR CORRECT ANSWER:
1 answer:
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Answer:
when the body is resting N = 246.96 N
when the body is resting on a tilted surface N = 212.12 N.
when the body is in a elevator N = 317.036 N
Explanation:
when the block is resting on a stationary surface the normal force is balanced by the weight of the body.
weight of the body = mg = 25.2×9.8 = 246.96 N
therefore normal force = 246.98 N.
when the block is resting on a tilted surface the normal force will be balanced by the component of the weight where Ф is the angle of inclination.
therefore N = mg
N= 212.12 N.
when the block is resting on a elevator that is accelerated upward the normal force will be the sum of weight and force due to acceleration ma
therefore N = 246.98 + 25.2×2.78
N = 317.036 N
Answer:
Ratio of resistance of heater A to resistance of heater B is 5.80
Explanation:
Consider C be the specific heat of water, R₁ and R₂ be the resistance of heater A and heater B respectively.
Given:
Mass of water in heater A, m₁ = 1 L
Mass of water in heater B, m₂ = 5.80 L
Initial temperature, T₀ = 20 ⁰C
Final temperature, T₁ = 90 ⁰C
Time, t = 5 min
Amount of heat required to raise the temperature of water by heaters A and B are given by:
Q₁ = m₁C(T₁ - T₀) and
Q₂ = m₂C(T₁ - T₀)
Ratio of power used by both the heaters A and B is:
Since, time t, temperature difference(T₁ - T₀) and specific heat C are same for both the heaters A and B. So, the above equation becomes:
...(1)
The relation to determine electrical power for both heaters A and B are:
and
Here V is the voltage applied to both the heaters and is equal.
So, the ratio of electrical power of heaters is:
....(2)
But according to the problem, the electrical power is converted into the thermal power. So,equation (1) and (2) are equal. Hence,
Substitute the suitable values in the above equation.