You understand the concepts all perfectly fine, just have applied them slightly incorrectly.
Firstly, the speed time graph is actually a triangle since the question says a steady acceleration from rest - i.e. it started at 0 and worked up to 2ms-1 in the space of that 10 seconds. The area under the graph is the distance, and a triangle area is found with bh/2, and in this case that is 10*2/2 = 10m - so the boat travelled 10 metres.
Work done as you correctly stated is fd - giving the part against water resistance as 3*10 = 30J
However, you forgot to do the last part - the key words are rate of work - this means Power. Power is Energy/Time, and this whole process occurred over 10 seconds. So whilst 30J of energy were expended due to the water resistance, this didn't all occur in no time. So we need to divide that by 10 to get the power. And 30/10 is 3J/s - and J/s is the same as W.
B) The velocity of a car reduced from 50 km/h to 35 km/h over one minute
Answer:
Condensation causes dew to form on blades of grass. This is because the water molecules react to the grass when it is heated, and the surroundings became cool. The molecules would bring to calm and turn to liquid.
Explanation:
I just took the test
A conjugate acid is formed from the base by accepting a proton from the acid .
A conjugate base is obtained from the Brownstead - Lowry acid when it looses a proton while the conjugate acid is obtained from the Brownstead - Lowry base when it accepts a proton. In the Brownstead - Lowry sense, acid base reaction involves the loss or gain of a proton.
Consider the hypothetical reaction; AH + :B ⇄ BH + :A. The specie BH is the conjugate acid while the specie :B is the Brownstead - Lowry base . The specie :A is the conjugate base while the specie AH is the Brownstead - Lowry acid.
Learn more about conjugate acid: brainly.com/question/10468518
Answer:
420
Explanation:
420 because 120 x 3 = 360
120/2 = 60 and 360 + 60 = 420
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