Answer:
-8.4°C
Explanation:
From the principle of heat capacity.
The heat sustain by an object is given as;
H = m× c× (T2-T1)
Where H is heat transferred
m is mass of substance
T2-T1 is the temperature change from starting to final temperature T2.
c- is the specific heat capacity of ice .
Note : specific heat capacity is an intrinsic capacity of a substance which is the energy substained on a unit mass of a substance on a unit temperature change.
Hence ; 35= 1× c× ( T2-(-25))
35= c× ( T2+25)
35 =2.108×( T2+25)
( T2+25)= 35/2.108= 16.60°{ approximated to 2 decimal place}
T2= 16.60-25= -8.40°C
C, specific heat capacity of ice is =2.108 kJ/kgK{you can google that}
Answer:
6666.67 Newtons
Explanation:
The formula F=ma (force is equal to mass multiplied by acceleration) can be used to calculate the answer to this question.
In this case:
- mass= 0.1mg= 1*10^-7 kg
- velocity= 4.00*10^3 m/s
- time= 6.00*10^-8 s
Using velocity and time, acceleration can be calculated as:
Substituting these values into the formula F=ma, the answer is:
- F= (1*10^-7)kg * (6.667*10^10) m/s²
- F= 6666.67 Newtons of force
The speed of the water is the greatest at point B
Answer:
The speed of the plank relative to the ice is:
Explanation:
Here we can use momentum conservation. Do not forget it is relative to the ice.
(1)
Where:
- m(g) is the mass of the girl
- m(p) is the mass of the plank
- v(g) is the speed of the girl
- v(p) is the speed of the plank
Now, as we have relative velocities, we have:
(2)
v(g/b) is the speed of the girl relative to the plank
Solving the system of equations (1) and (2)
I hope it helps you!
Answer:
Explanation:
Near point = 56 cm .
near point of healthy person = 25 cm
person suffers from long sightedness
convex lens will be required .
object distance u = 25 cm
image distance v = 56 cm
both will be negative as both are in front of the lens.
lens formula
I/v - 1 / u = 1/f
- 1/56 +1/25 = 1/f
- .01785 + .04 = 1/f
1/f = .02215
f = 45.15 cm .
