Answer:
Explanation:
Time to cover first 100 km = 1 hour.
time remaining = 3.15 - 1 = 2.15 hour .
Time to cover next 42 km = 1 hour .
Time remaining = 2.15-1 = 1.15 hour.
Distance to be covered = 310 - 142
= 168 km
least speed needed = distance remaining / time remaining
= 168 / 1.15
= 146.08 km / h .
<span>When an object travels in a curved path, there must be a force acting toward the center of the circular trajectory. This force is called "centripetal force", and it cause an acceleration of the object, called "centripetal acceleration". The effect of this acceleration is that the velocity of the object changes in direction: however if the circular motion is uniform, the speed (=the magnitude of the velocity) does not change. In this case, the magnitude of the centripetal force is given by
</span>

<span>
where m is the mass of the object, v its velocity, and r the radius of the circular path.</span>
Answer:
R = 5.73 m
Explanation:
For an angle of rotation through 21 degree we know that
arc length is given as

now we know that
Arc = 2.1 m
Angle = 21 degree

so now we have



the water specific heat will remain at 4.184.
Incomplete question as the unit of volume is not written correctly.So the complete question is here:
A straightforward method of finding the density of an object is to measure its mass and then measure its volume by submerging it in a graduated cylinder. What is the density of a 240-g rock that displaces 89.0 cm³?
Answer:

Explanation:
Given data
Mass m=240g
Volume V=89.0 cm³
To find
Density d
Solution
If rock displaces 89.0 cm³ of water means volume of rock is also 89cm³
So
