What’s the rest of the question or is that it?
Complete Question
A wave is described by y(x,t) = 0.1 sin(3x + 10t), where x is in meters, y is in centimetres and t is in seconds. The angular wave frequency is
Answer:
The value is 
Explanation:
From the question we are told that
The equation describing the wave is y(x,t) = 0.1 sin(3x + 10t)
Generally the sinusoidal equation representing the motion of a wave is mathematically represented as

Where w is the angular frequency
Now comparing this equation with that given we see that

Answer:
4.2s
Explanation:
Given parameters:
Power = 2190W
Mass of box = 1.47 x 10⁴g
distance = 6.34 x 10⁴mm
Unknown:
Time = ?
Solution:
Power is the rate at which work is done;
Mathematically;
Power =
Time =
Work done = weight x height
convert mass to kg;
100g = 1kg;
1.47 x 10⁴g = 14.7kg
convert the height to m;
1000mm = 1m
6.34 x 10⁴mm gives 63.4m
Work done = 14.7 x 9.8 x 63.4 = 9133.4J
Time taken =
= 4.2s
Answer: B.
Capacitors prevent current from moving through a circuit
Explanation:
If a direct voltage is applied on the capacitor, no conduction current flows through the capacitor if its insulating medium is perfect insulator. This is due to the fact that there are no free charge carriers in such medium. Basically the real insulator contains very few charge carriers and therefore a very small leakage current passes in the capacitor depending on the conductivity of the insulator.
If an alternating voltage is applied on the capacitor, a displacement current passes through the capacitor irrespective of the insulating medium. This current is termed also the capacitive current. It flows because of changing electric displacement with time.