The three types of heat transfer are conduction convection and radiation. <u>Explanation:</u>
- Heat transfer happens only when there is said to be a temperature difference. (i.e) heat transfer occurs with a higher temperature region to a lower temperature region.
- Heat is transferred usually via some medium in the case of convection and conduction whereas in the radiation no medium is required ( i.e it take place in a vacuum ).
- Conduction is a type of heat transfer that is mainly a character for the conducting and semiconducting solid material.
- Convection is the heat transfer method that usually takes place in the liquids and gases.
- Radiation is the heat transfer process in which heat is transferred via infrared or electromagnetic waves.
Answer:
F = 2349.6 N
Explanation:
We can solve this exercise using the relationship of momentum and momentum
I = Δp
I = F t
As the woman accelerates at a distance of 29.1 m to go from rest to 56.8 m / s, we can use the kinematics to find the acceleration
v² = v₀² + 2 a x
v₀ = 0
a = v / 2x
a = 56.8 2/2 29.1
a = 55.43 m / s²
Let's look for the time you need to get this speed
v = v₀ + a t
t = v / a
t = 56.8 / 55.43
t = 1,025 s
Let's clear the average force momentum from the momentum
F t = m v- m v₀
F = mv / t
F = 42.4 56.8 / 1.025
F = 2349.6 N
Answer:
s = 11.46 m
Explanation:
Since, the reaction time is 0.75 s. Hence, the brakes shall be applied after this time. So, the car will start to slow down after covering a distance at the constant speed during this time. This distance can be given as follows:
s = vt
where,
s = distance covered by car before slowing down = ?
v = speed of car = (55 km/h)(1 h/3600 s)(1000 m/1 km) = 15.28 m/s
t = reaction time = 0.75 s
Therefore,
s = (15.28 m/s)(0.75 s)
<u>s = 11.46 m</u>
Answer:Friction force
Explanation:
The frictional force is responsible for stopping the moving object.
The friction force is provided by nature in the form of air resistance, fluid resistance, Surface resistance.
For surface resistance, the friction force is of two types namely kinetic friction force and static friction force.
Static friction acts when the object is stationary and a force is applied to cause the motion while kinetic friction acts when the body starts moving.
kinetic friction is lesser is in magnitude as compared to static friction.
• Objects “fall” toward the center of Earth. (TRUE)
Since the gravitational force between earth and any object is always along the line joining the centers of two so all the objects near the surface of earth will always feel force towards the centre of the earth due to gravity.
• Objects are pulled by Earth but do not pull on Earth. (FALSE)
Since gravitational force will always follow Newton's III law as per which every action has equal and opposite reaction force so object near the surface of earth will also pull the earth as earth is pulling the object towards the center.
• Objects accelerate at a rate of 9.8 m/s each second. (TRUE)
Since acceleration due to gravity of Earth is 9.8 m/s^2 so here we can say that all objects near the surface of earth will accelerate towards the center of earth at rate of 9.8 m/s^2 due to gravitational pull.
• Objects travel at a rate of 9.8 m/s to are the center of Earth. (FALSE)
Since earth is pulling all objects near its surface with gravitational force so objects can not move at constant speed but it will move with constant acceleration.
• Objects are pulled by Earth more strongly than they pull on Earth. (FALSE)
Since gravitational force will always follow Newton's III law which say every action has equal and opposite reaction so we can say that force due to all objects on earth will be same as the force of earth on the object.