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:
The frictional torque is 
Explanation:
From the question we are told that
The mass attached to one end the string is 
The mass attached to the other end of the string is 
The radius of the disk is 
At equilibrium the tension on the string due to the first mass is mathematically represented as

substituting values


At equilibrium the tension on the string due to the mass is mathematically represented as



The frictional torque that must be exerted is mathematically represented as

substituting values


Answer: 1: (A) They allow electrons to move freely between them. 2: (C) they change their positions relative to one another.
Explanation:
Answer:
The efficiency of the system is 63.7 %
Explanation:
Given;
input power of the motor, = 1.5 kW = 1,500 W
mass of the car lifted, m = 1300 kg
height through which the car was lifted, h = 1.8 m
time, t = 24 s
The output power of the motor is calculated as;
Output Power = F x v
= (mg) x (d/t)
= (1300 x 9.8) x (1.8 / 24)
= 12,740 x 0.075
= 955.5 W
The efficiency of the system is calculated as;

The correct answer is 63.7%
Answer:
Large spherical regions from which no light is detected
Explanation:
A black hole is an object that has an extremely high density such that it possesses very powerful gravitational force that prevents the escape of all objects including light from it, and consumes nearby objects.
Due to the power of the gravitational force of a black hole, at the center, objects are infinitesimally compressed resulting in the inapplicability of the concept of space and time and the location is known as a singularity
Therefore, the search for black holes involves searching for <em>large spherical regions from which no light is detected</em>.