Before coming into conclusion first we have to understand the direction of heat flow.
Heat is the transferred thermal energy from one body to another body due to the temperature difference just like water flows from higher level to lower level.
Whenever two bodies having different temperature come closer to each other heat will flow from hotter body to cooler one if no external work is done. The heat flow may be through any of the ways i.e conduction,radiation or convection. Hence temperature difference is the parameter which gives the direction of heat flow.
The temperature is also considered as a measure of average kinetic energy of the substance.The thermal energy does not give the direction heat flow. Heat may flow from the body having low thermal energy but at higher temperature to the body having higher thermal energy but at low temperature. The reverse does not happen naturally .
In example 1 there is fire and air. Obviously fire is at high temperature and air at low temperature.So heat will flow from object 1 to object 2.
In example 2 there is a metal at 80 degree Celsius and another metal at 12 degree Celsius .So heat will flow from object 1 to object 2
In example 3 we have cooler ocean and warm air. So the heat will flow from object 2 to object 1.
In example 4 we have a tool with high thermal energy and a material with little thermal energy.We already know that thermal energy can not determine the direction of heat flow. Here the temperature of each substance is not given.The kinetic energy is part of thermal energy.So there is the chance of higher kinetic energy of the tool for having higher thermal energy .At that time the heat will flow object 1 to object 2.Otherwise the reverse will occur. So it is a special case.
As per the question only option 4 is correct which tells that heat will flow from object 1 to object 2 in examples 1,2,4, and heat will flow from object 2 to 1 in example 3. Other options violate the fundamental law of thermodynamics.
To make a base line mark to know where she started measuring the snails movement, at the end of the day she can measure from her first line to her last to see how far the snail went.
Hope this helped!
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Answer:the line away from the spacecraft should be straight down (perpendicular to it). Label this M. This is the force of the moon on the spacecraft. A minuscule line upward from the moon towards the spacecraft shows the force of the spacecraft on the moon. Should be directly below the spacecraft and pointed straight up at it.
Explanation:
Answer:
In classical mechanics, kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. For example, if a an object with a mass of 10 kg (m = 10 kg) is moving at a velocity of 5 meters per second (v = 5 m/s), the kinetic energy is equal to 125 Joules, or (1/2 * 10 kg) * 5 m/s2.
As we know from the equation of kinematics

here it starts from rest
final angular speed will become 90 rad/s in time interval of t = 10 s
now we will have


So it will stop after 50 seconds of constant deceleration.