Answer:
<h2>
3,343.68kJ </h2>
Explanation:
Heat energy used up can be calculated using the formula:
H = mcΔt
m = mass oof the object (in kg) = 20kg
c = specific heat capacity of water = 4179.6J/kg°C
Δt change in temperature = 80-40 = 40°C
H= 20* 4179.6 * 40
H = 3,343,680Joules
H = 3,343.68kJ
You are at rest with respect to the car.
You are in motion with respect to the School.
The distance in meters she would have moved before she begins to slow down is 11.25 m
<h3>
LINEAR MOTION</h3>
A straight line movement is known as linear motion
Given that Ann is driving down a street at 15 m/s. Suddenly a child runs into the street. It takes Ann 0.75 seconds to react and apply the brakes.
To know how many meters will she have moved before she begins to slow down, we need to first list all the given parameters.
From definition of speed,
speed = distance / time
Make distance the subject of the formula
distance = speed x time
distance = 15 x 0.75
distance = 11.25m
Therefore, the distance in meters she would have moved before she begins to slow down is 11.25 m
Learn more about Linear motion here: brainly.com/question/13665920
Answer:
Explanation:
Given

Frictional Force is balanced by force due to car acceleration
Frictional force 




Comparative investigation is a research method that makes comparison across different countries of the world. Limitation : data set in different countries may be defined differently. Benefit : the method is flexible.