Answer: for 1 is number 1
and for 2 is 3
Explanation:
Answer:
1.7 seconds
Explanation:
To clear the intersection, the total distance to be covered = 59.7 + 25 =84.7m
first we need to find the initial speed to just enter the intersection by using the third equation of motion
v^2 - u^2 = 2*a*s
45^2 - u^2 = 2 * -5.7 * 84.7
u^2 = 45^2 +965.58
u^2 = 2990.58
u = 54.7 m/s
Now for time we apply the first equation of motion
v-u =a * t
t = (v-u)/a = (45 - 54.7)/-5.7 = 1.7seconds
Answer:

Explanation:
- We have to make a hollow sphere of inner radius
and outer radius
.
Then the mass of the material required to make such a sphere would be calculated as:
Total volume of the spherical shell:

And the volume of the hollow space in the sphere:

Therefore the net volume of material required to make the sphere:


- Now let the density of the of the material be
.
<u>Then the mass of the material used is:</u>


The answer would be B, George Darwin :)
Answer:
<u>We are given:</u>
u = 2.5 m/s
a = 0.2 m/s/s
t = 25 seconds
v = v m/s
<u>Solving for 'v':</u>
From the first equation of motion:
v = u + at
Replacing the values
v = 2.5 + (0.2)(25)
v = 2.5 + 5
v = 7.5 m/s