The kinetic energy (in joules, J) of an object travelling at a speed well below the speed of light is given by:
E = 1/2 m v2
where m is the mass in kilograms (kg), and v is the speed in metres per second (m s-1).
When the car is at rest, its kinetic energy is zero. At a speed of 25 m s-1, its kinetic energy is:
E = 1/2 x 950 kg x (25 m s-1)2
= 475 x 625
= 296 875 J
So it gained 296 857 joules of energy over a period of 5 seconds. The power is the rate at which energy is gained (or used up, depending on the situation), in joules per second (J s-1), which may also be called watts (W). The average power gained here is given by:
P = E / t
where t is the time (in seconds, s) that it took to transfer the energy E. So:
P = 296 875 / 5
= 59 375 W
or 59.375 kilowatts (kW)
You can round this to 59 kW, giving the answer to 2 significant figures (since the numbers in the question are quoted to that degree of accuracy).
You need to make your question clearer.
.47 watt
Power is measured in watts, or joules per second. So in 90 seconds, 1200 joules of work is equal to 1200/90 watts or 13.3 watts.
Power is energy per unit time. So, the required power is 900/90 = 10 Watts.
There are 420 seconds.
You need to make your question clearer.
Power = Work divided by seconds.or in other words....Power = work/seconds.Clear explanation: Power is equal to:How much work is done (in joules) divided by the seconds of how much time did the work took.For example:Problem: A construction worker pushes the wheelbarrow with the power of 50 J per 2 seconds how much power does he use?Answer: 50 J divided by 2 s is 25 W so, the power is equal to 25 watts.
7.5 watts
27,000 J
Power (Watts) is Joules (energy) per Second (time) so divide the number of joules by the number of seconds. 104/60 = 1.733 Watts
Power = (energy used) / (time to use that much energy) = 40/5 = 8 watts
Accelerates wear and tear
.47 watt
Power is measured in watts, or joules per second. So in 90 seconds, 1200 joules of work is equal to 1200/90 watts or 13.3 watts.
3000
Power is energy per unit time. So, the required power is 900/90 = 10 Watts.
Power = (energy) / (time) =(200 newtons x 4 meters) / (4 seconds) =200 newton-meters per second = 200 watts