Answer:
Explanation:
Applied force, F = 18 N
Coefficient of static friction, μs = 0.4
Coefficient of kinetic friction, μs = 0.3
θ = 27°
Let N be the normal reaction of the wall acting on the block and m be the mass of block.
Resolve the components of force F.
As the block is in the horizontal equilibrium, so
F Cos 27° = N
N = 18 Cos 27° = 16.04 N
As the block does not slide so it means that the syatic friction force acting on the block balances the downwards forces acting on the block .
The force of static friction is μs x N = 0.4 x 16.04 = 6.42 N .... (1)
The vertically downward force acting on the block is mg - F Sin 27°
= mg - 18 Sin 27° = mg - 8.172 ... (2)
Now by equating the forces from equation (1) and (2), we get
mg - 8.172 = 6.42
mg = 14.592
m x 9.8 = 14.592
m = 1.49 kg
Thus, the mass of block is 1.5 kg.
Answer:
1 Ampere.
Explanation:
From the question given above, the following data were obtained:
Resistor 1 (R₁) = 20 ohm
Resistor (R₂) = 20 ohm
Voltage (V) = 10 V
Current (I) =?
Next, we shall determine the equivalent resistance in the circuit. This can be obtained as follow:
Resistor 1 (R₁) = 20 ohm
Resistor (R₂) = 20 ohm
Equivalent Resistance (R) =?
Since the resistors are in parallel connection, the equivalent resistance can be obtained as follow:
R = (R₁ × R₂) / (R₁ + R₂)
R = (20 × 20) / (20 + 20)
R = 400 / 40
R = 10 ohm
Finally, we shall determine the total current in the circuit. This can be obtained as illustrated below:
Voltage (V) = 10 V
Equivalent Resistance (R) = 10 ohm
Current (I) =?
V = IR
10 = I × 10
Divide both side by 10
I = 10 / 10
I = 1 Ampere
Therefore, the total current in the circuit is 1 Ampere.
Sunlight emits more energy than artificial light. Sunlight is better and healthier than most artificial lights and helps plants to grow more.
Answer:
457.81 Hz
Explanation:
From the question, it is stated that it is a question under Doppler effect.
As a result, we use this form
fo = (c + vo) / (c - vs) × fs
fo = observed frequency by observer =?
c = speed of sound = 332 m/s
vo = velocity of observer relative to source = 45 m/s
vs = velocity of source relative to observer = - 46 m/s ( it is taking a negative sign because the velocity of the source is in opposite direction to the observer).
fs = frequency of sound wave by source = 459 Hz
By substituting the the values to the equation, we have
fo = (332 + 45) / (332 - (-46)) × 459
fo = (377/ 332 + 46) × 459
fo = (377/ 378) × 459
fo = 0.9974 × 459
fo = 457.81 Hz
