The magnitude<span> of a </span>velocity<span> vector is </span>called<span> speed. Supposethat a wind is blowing in from the direction at a speed of 50 km/h. (This meansthat the direction from which the wind blows is west of the northerly direction.) Apilot is steering a plane in the direction at an airspeed (speed in still air) of250 km/h
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Answer:
23.52 m/s
Explanation:
The following data were obtained from the question:
Time taken (t) to reach the maximum height = 2.4 s
Acceleration due to gravity (g) = 9.8 m/s²
Initial velocity (u) =..?
At the maximum height, the final velocity (v) is zero. Thus, we can obtain how fast the rock (i.e initial velocity)
was thrown as follow:
v = u – gt (since the rock is going against gravity)
0 = u – (9.8 × 2.4)
0 = u – 23.52
Collect like terms
0 + 23.52 = u
u = 23.52 m/s
Therefore, the rock was thrown at a velocity of 23.52 m/s.
Answer: 1026s, 17.1m
Explanation:
Given
COP of heat pump = 3.15
Mass of air, m = 1500kg
Initial temperature, T1 = 7°C
Final temperature, T2 = 22°C
Power of the heat pump, W = 5kW
The amount of heat needed to increase temperature in the house,
Q = mcΔT
Q = 1500 * 0.718 * (22 - 7)
Q = 1077 * 15
Q = 16155
Rate at which heat is supplied to the house is
Q' = COP * W
Q' = 3.15 * 5
Q' = 15.75
Time required to raise the temperature is
Δt = Q/Q'
Δt = 16155 / 15.75
Δt = 1025.7 s
Δt ~ 1026 s
Δt ~ 17.1 min
Answer:
Phase Difference
Explanation:
When the sound waves have same wavelength, frequency and amplitude we just need the phase difference between them at a particular location to determine whether the waves are in constructive interference or destructive interference.
Interference is a phenomenon in which there is superposition of two coherent waves at a particular location in the medium of propagation.
When the waves are in constructive interference then we get a resultant wave of maximum amplitude and vice-versa in case of destructive interference.
- For constructive interference the waves must have either no phase difference or a phase difference of nλ, where n is any natural number.
- For destructive interference the waves must have a phase difference of n×0.5λ, where n is any odd number.
Answer: piece of paper cut into a triangle
Explanation:
A plane surface lifted at an angle to horizontal from one edge is said to be an inclined plane. A wedge, a ramp or a screw are examples of a forms of inclined plane. A screw is like a inclined plane wound on a cylinder. These are simple machines. On the other hand, a piece of paper cut into a triangle is not an inclined plane as it does rise at an angle from horizontal. It is not a machine.
