Answer:
230.4 s
Explanation:
The speed of car A is

and the distance travelled is

so the time taken for car A is

The speed of car B is

and the distance travelled is

so the time taken for car B is

So the difference in time is

Which corresponds to

so car B arrived 230.4 s before car A.
Yes it would get colder because people help people learn through experiences with no one to help teach the world would be a cold lifeless place.
Answer:
The weight lifter would not get past this sticking point.
Explanation:
Generally torque applied on the weight is mathematically represented as
T = F z
To obtain Elbow torque we substitute 4000 N for F (the force ) and 2cm
for z the perpendicular distance
So Elbow Torque is 

To obtain the torque required we substitute 300 N for F and 30cm 
So the Required Torque is 

Now since
it mean that the weight lifter would not get past this sticking point
Given gravitational potential energy when he's lifted is 2058 J.
Kinetic energy is transferred to the person.
Amount of kinetic energy the person has is -2058 J
velocity of person = 7.67 m/s².
<h3>
Explanation:</h3>
Given:
Weight of person = 70 kg
Lifted height = 3 m
1. Gravitational potential energy of a lifted person is equal to the work done.

Gravitational potential energy is equal to 2058 Joules.
2. The Gravitational potential energy is converted into kinetic energy. Kinetic energy is being transferred to the person.
3. Kinetic energy gained = Potential energy lost = 
Kinetic energy gained by the person = (-2058 kg.m/s²)
4. Velocity = ?
Kinetic energy magnitude= 
Solving for v, we get

The person will be going at a speed of 7.67 m/s².
Answer:
Melt.
Explanation:
When rocks melt, they do so slowly and gradually because most rocks are made of several minerals, which all have different melting points; moreover, the physical and chemical relationships controlling the melting are complex. As a rock melts, for example, its volume changes. When enough rock is melted, the small globules of melt link up and soften the rock.
Under normal conditions, mantle rock like peridotite shouldn't melt in the Earth's upper mantle. However, by adding water you can lower the melting point of the rock. Alternatively, by decompressing the rock, you can bring it to a pressure where the melting point is lower. In both cases, basalt magma will form and considering it is hotter and less dense than the surrounding rock, it will percolate towards the surface and some of that erupts.