in which of the following is the most work being done by roy and which example roy doing no work? a)roy lifts a 5kg radio up 1 meter b) roy holds a 5 kg radio at a height of 1meter for 3 hours. c)roy lifts a 10 kg TV up 1 meter d)roy lifts a 10 kg TV up 2 meters. e) roy drops a 10 kg TV from a height of 23 meters.
10 * 2 is max (d)
The 0 * 23 = 0 , no work by roy , (e)
To determine the most work being done by Roy and the example where Roy is doing no work, we need to calculate the work done in each scenario.
Work (W) is defined as the product of the force applied (F) and the distance moved in the direction of the force (d):
W = F * d
Let's evaluate each scenario:
a) Roy lifts a 5 kg radio up 1 meter:
In this case, the force required to lift the radio is equal to the weight of the radio, which can be calculated using the formula: F = m * g, where m is the mass and g is the acceleration due to gravity (approximately 9.8 m/s^2).
F = 5 kg * 9.8 m/s^2 = 49 N
W = F * d = 49 N * 1 m = 49 Joules
b) Roy holds a 5 kg radio at a height of 1 meter for 3 hours:
In this scenario, Roy is not moving the radio, so no work is being done. The force required to hold the radio against gravity is equal to its weight, but since there is no displacement, the work is zero.
c) Roy lifts a 10 kg TV up 1 meter:
Using the same process as in scenario (a):
F = m * g = 10 kg * 9.8 m/s^2 = 98 N
W = F * d = 98 N * 1 m = 98 Joules
d) Roy lifts a 10 kg TV up 2 meters:
Using the same process as in scenario (a):
F = m * g = 10 kg * 9.8 m/s^2 = 98 N
W = F * d = 98 N * 2 m = 196 Joules
e) Roy drops a 10 kg TV from a height of 23 meters:
When an object is dropped, the work done on it is given by the potential energy it possesses due to its height.
Potential energy (PE) is given by the formula: PE = m * g * h
PE = 10 kg * 9.8 m/s^2 * 23 m = 2260 Joules
Since the work done on the TV is equal to the potential energy when it is dropped, the work done here is 2260 Joules.
In conclusion, the scenario where the most work is being done by Roy is when he drops the 10 kg TV from a height of 23 meters, where the work done is 2260 Joules. The example where Roy is doing no work is when he holds a 5 kg radio at a height of 1 meter for 3 hours.