A 5-kg rock is lifted 2 meters in 5 seconds. How much work is done? How much power is done?
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work=weight*heightLifted
power= work/timeinseconds
The answer is 2 W
To calculate the work done, you need to multiply the force exerted on the rock by the distance it is lifted. In this case, the force can be calculated using the equation F = m * g, where m is the mass of the rock and g is the acceleration due to gravity (approximately 9.8 m/s^2). The distance can be directly obtained from the problem, which is 2 meters.
Let's calculate the work done:
1. Determine the force: F = m * g = 5 kg * 9.8 m/s^2 = 49 N (Newtons)
2. Calculate the work done: W = F * d = 49 N * 2 m = 98 Joules (J)
Therefore, the work done to lift the 5-kg rock 2 meters is 98 J.
To calculate power, you need to divide the work done by the time it took to do that work. In this case, the time given is 5 seconds.
Let's calculate the power:
1. Determine the work done: W = 98 J
2. Determine the time taken: t = 5 s
3. Calculate the power: P = W / t = 98 J / 5 s ≈ 19.6 Watts (W)
Therefore, the power exerted to lift the 5-kg rock 2 meters in 5 seconds is approximately 19.6 watts.