If a 400 watt motor is left on for 10 minutes, assuming no energy is lost to friction, how fast could a 100 kg cart be moving?

69.28 m/s

Explanation:

From the question given above, the following data were obtained:

Power = 400 Watt

Time (t) = 10 minutes

Mass (m) = 100 Kg

Velocity (v) =?

Next, we shall convert 10 mins to seconds (s). This can be obtained as follow:

1 min = 60 s

Therefore,

10 mins = 10 × 60

10 mins = 600 s

Next, we shall determine the energy. This can be obtained as follow:

Power = 400 Watt

Time (t) = 600 s

Energy (E) =?

E = Pt

E = 400 × 600

E = 240000 J

Finally, we shall determine how fast the cart is moving. This can be obtained as illustrated below:

Mass (m) = 100 Kg

Energy (E) = Kinetic energy (KE) = 240000 J

Velocity (v) =?

KE = ½mv²

240000 = ½ × 100 × v²

240000 = 50 × v²

Divide both side by 50

v² = 240000 / 50

v² = 4800

Take the square root of both side

v = √4800

v = 69.28 m/s

Thus, the cart is moving with a speed of 69.28 m/s

when it gains or loses electrons

hypothesising or postulating