A scalar is a quantity that is fully described by a magnitude only. It is described by just a single number. Some examples of scalar quantities include speed, volume, mass, temperature, power, energy, and time. A vector is a quantity that has both a magnitude and a direction.
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A: The battery is a store of internal energy (shown as chemical energy). The energy is transferred through the wires to the lamp, which then transfers the energy to the surroundings as light. These are the useful energy transfers - we use electric lamps to light up our rooms.
B: In the case of the light bulb the 95J of energy transferred as heat is wasted energy as it is not useful because the purpose of the device is to produce light.
SORRY I ONLY HAVE ANSWERS FOR A AND B
For the same reason that you can skate around a curve at constant speed but not with constant velocity.
The DIRECTION you're going is part of your velocity, but it's not part of your speed.
If the DIRECTION changes, that's a change of velocity.
The object doesn't have to change speed to have a different velocity. A change of direction is enough to do it.
And any change of velocity is called acceleration.
Answer:
Find answers below.
Explanation:
Given the following data;
Voltage = 220V
Current = 15 A
a. To find the power;
Power = current * voltage
Power = 15 * 220
Power = 3300 Watts
b. To find the energy;
Time = 8 hours = 60 * 60 * 8 = 28800 seconds
Energy = power * time
Energy = 3300 * 8
Energy = 26400
Energy = 26.4 Kwh
c. Cost = 13 cents
Cost = 13 * 31 * 26.4
Cost = 106392 cents
Answer:
B. x - t graph
Explanation:
A position-time (x-t) graph is a graph of the position of an object against (versus) time.
Generally, the slope of the line of a position-time (x-t) graph is typically used to determine or calculate the velocity of an object.
An instantaneous velocity can be defined as the rate of change in position of an object in motion for a short-specified interval of time. Thus, an instantaneous velocity is a quantity that can be found by measuring the slope of a line that is tangent to a point on the graph.
Hence, the x - t graph also referred to as the position-time graph is used for determining the instantaneous velocity from the slope.
<u>For example;</u>
Given that the equation of motion is S(t) = 4t² + 2t + 10. Find the instantaneous velocity at t = 5 seconds.
Solution.
Differentiating the equation, we have;
Substituting the value of "t" into the equation, we have;
S(5) = 42 m/s.