Answer:
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement. Put another way, speed is a scalar value, while velocity is a vector. ... In its simplest form, average velocity is calculated by dividing change in position (Δr) by change in time (Δt).
Explanation:
4 hydrogen atoms.. l hope it helped
Answer:
180 kJ
Explanation:
Given that:
Mass (m) = 5 kg
Initial temperature (T1) = 28°C
Final temperature (T2) = 68°C
The change in temperature (ΔT) = T2 - T1 = 68°C - 28°C = 40°C
Specific heat capacity of aluminium (c) = 900 J/kg°C
The quantity of heat energy required (q) is given by:
q = mcΔT
q = 5 kg × 900 J/kg°C × 40°C
q = 180000 Joules
q = 180 kJ
Therefore 180 kJ is required to raise the temperature of aluminium from 28°C to 68°C.
Answer:
baking the cake batter
Explanation:
Baking the cake batter will indicate that chemical change has occurred here. What is a chemical change?
- A chemical change is one in which a new kind of matter is formed.
- It is usually accompanied by energy either evolution or absorption of energy in form of heat or light or both.
- The process is irreversible.
- When the batter bakes, a new substance different from the cake mix is obtainable.
- We cannot get back the ingredient from this baked cake. It is impossible.
- This is good indicator of chemical change.
Answer:
25N
Explanation:
Given parameters:
Power of the motor = 125W
Average speed = 5m/s
Unknown:
Force supplied to the motor = ?
Solution:
Work done is the force applied to move a body through a particular distance;
Work done = Force x distance
Also,
Work done = Power x time
So;
Force x distance = Power x time
since force is the unknown;
Force = 
Speed = 
Force = 
Now solve;
Force = 
= 25N
