Answer: 9130 joules
Explanation:
Workdone by wheelbarrow = ?
Time = 11 seconds
Power = 830 watts
Recall that power is the rate of doing work. Thus, power is workdone divided by time taken.
i.e Power = (workdone/time)
830 watts = Workdone / 11 seconds
Workdone = 830 watts x 11 seconds
Workdone = 9130 joules
Thus, 9130 joules of work is required to get the wheelbarrow across the yard.
Answer:
Explanation:
graph would be a straight line from (0, 0) to (400, 8)
Plot points are
PE = mgh
50(0) = 0 J
50(2) = 100 J
50(4) = 200 J
50(6) = 300 J
50(8) = 400 J
Answer:

Explanation:
According to the statement of the problems, the following identity exists:


After some algebraic handling, the ratio is obtained:


Answer:
The change in the centripetal acceleration of the brother,
Δa = V₂²/R - V₁²/R
Explanation:
Given data,
A sister spins her brother in a circle of radius, R
The angular velocity of the brother, ω₁ = V₁/R
The angular velocity of the brother, ω₂ = V₂/R
The centripetal acceleration is given by the relation
a = V²/R
Therefore change in the centripetal acceleration of the brother,
Δa = V₂²/R - V₁²/R
Answer:
(A) Q = 2.26×10⁶J
(B) ΔT = 9°C
(C)
Explanation:
We have been given the mass of the hiker, the volume of water from which we can calculate the mass knowing that the density if water is 1000kg/m³.
Evaporation is a phase change and occurs at a constant temperature. We would use the latent heat of vaporization to calculate the amount of heat evaporated.
We would then equate this to the heat change it brings about in the hiker's body and then calculate the temperature drop.
See the attachment below for full solution.