Explanation:
Height of object =5cm
Position of object, u=−25cm
Focal length of the lens, f=10cm
Position of image, v=?
We know that,
v
1
−
u
1
=
f
1
v
1
+
25
1
=
10
1
v
1
=
10
1
−
25
1
So,
v
1
=
50
(5−2)
That is,
1
=
50
3
So,
v=
3
50
=16.66cm
Thus, distance of image is 16.66cm on the opposite side of lens.
Now, magnification =
u
v
That is,
m=
−25
16.66
=−0.66
Also,
m=
heightofobject
heightofimage
or
−0.66=
5cm
heightofimage
Therefore, Height of image =3.3cm
Answer:
Option 1 is endothermic
Option 2 is exothermic
Explanation:
In Chemistry, Exothermic reactions are reactions whereby heat energy is transferred to the surroundings and the temperature of the surroundings increases. Endothermic reactions are those whereby heat energy from the surroundings is absorbed and thereby making the temperature of the surroundings to decrease.
This means in simple terms that endothermic reactions will have heat on the reaction side of the equation while exothermic will have heat on the product side of the equation.
Thus;
Option 1 is endothermic since it has heat absorbed on the reactant side.
Option 2 is exothermic since it gives off heat on the product side.
Explanation:
Vectors are quantities that has both magnitude and direction. A vector is described in terms of quantity and the direction it is headed.
There are different forms of vectors that are used in our daily life.
- When we describe the motion of a car and the direction it is heading, we are simply talking about its velocity which is a vector.
- When we say James treks 2km from his school to the house everyday, we are simply describing his displacement.
- When we apply a force to push the table from one corner of the room to another point, is simply a vector
- When we change position, it is a vector application.
We use the formula, to calculate the volume of water displaced by concrete canoe,
Here, W is the weight of concrete canoe and 
is the specific weight of water and its value is 
.
So,
.
Now the volume of water occupied in ultra lightweight kevlar canoe,
Here, w is weight of kevlar canoe.
So,
Thus, the volume of water displaced,
.
Hence, the volume of water displaced canoe compared to an ultra-lightweight kevlar canoe is 
Answer:
59.4 meters
Explanation:
The correct question statement is :
A floor polisher has a rotating disk that has a 15-cm radius. The disk rotates at a constant angular velocity of 1.4 rev/s and is covered with a soft material that does the polishing. An operator holds the polisher in one place for 4.5 s, in order to buff an especially scuff ed area of the floor. How far (in meters) does a spot on the outer edge of the disk move during this time?
Solution:
We know for a circle of radius r and θ angle by an arc of length S at the center,
S=rθ
This gives
θ=S/r
also we know angular velocity
ω=θ/t where t is time
or
θ=ωt
and we know
1 revolution =2π radians
From this we have
angular velocity ω = 1.4 revolutions per sec = 1.4×2π radians /sec = 1.4×3.14×2×= 8.8 radians / sec
Putting values of ω and time t in
θ=ωt
we have
θ= 8.8 rad / sec × 4.5 sec
θ= 396 radians
We are given radius r = 15 cm = 15 ×0.01 m=0.15 m (because 1 m= 100 cm and hence, 1 cm = 0.01 m)
put this value of θ and r in
S=rθ
we have
S= 396 radians ×0.15 m=59.4 m
