Answer:
The efficiency of the system is 63.7 %
Explanation:
Given;
input power of the motor, = 1.5 kW = 1,500 W
mass of the car lifted, m = 1300 kg
height through which the car was lifted, h = 1.8 m
time, t = 24 s
The output power of the motor is calculated as;
Output Power = F x v
= (mg) x (d/t)
= (1300 x 9.8) x (1.8 / 24)
= 12,740 x 0.075
= 955.5 W
The efficiency of the system is calculated as;

The correct answer is 63.7%
Answer:
60 boxes
Explanation:
The work done by lifting a single box is equal to the force applied (the weight of the box) times the displacement of the box:

Power is related to the work done by the equation:

where W is the work done and t is the time. In this problem, we are told that the power used is P=60.0 W, while the time taken is t = 1 min = 60 s, so the total work done must be

Therefore, the number of boxes that she has to lift in order to use this power is the total work divided by the work done in lifting each box:

Answer:
volume is 700 mL
Explanation:
pressure = 2 atm
volume = 350 mL = 0.350 L
to find out
volume
solution
we will apply here equation that is
P1×V1 = P2×V2 ..............1
here P1 = 2 and V1 = 0.350 and P2 = 1 for standard atmospheric pressure
so put all value here in equation 1 and get V2 volume
2 × 0.350 = 1 × V2
V2 = 0.700 L
V2 = 700 mL
so volume is 700 mL
Thus, a swinging pendulum has its greatest kinetic energy and least potential energy in the vertical position, in which its speed is greatest and its height least; it has its least kinetic energy and greatest potential energy at the extremities of its swing, in which its speed is zero and its height is greatest.