Answer:
Assuming there is no heat loss to the surrounding.
Heat lost by iron equals heat gained by water.
0.2(450)(50-x)=0.2(4200)(x-30)
x=31.94 °C
Explanation:
Calculate its average speed in meters per second
Answer:
5.77 m/s
Explanation:
Speed= Distance/Time
Distance= 40+ half of 40= 40+20= 60 m
Time= 8.8+1.6=10.4 s
Average speed= 60/10.4=5.769230769 m/s
Approximately, the average speed is 5.77 m/s
Answer:
Explanation:
Given that:
the initial angular velocity 
angular acceleration
= 4.44 rad/s²
Using the formula:

Making t the subject of the formula:

where;

∴

t = 0.345 s
b)
Using the formula:

here;
= angular displacement
∴



Recall that:
2π rad = 1 revolution
Then;
0.264 rad = (x) revolution

x = 0.042 revolutions
c)
Here; force = 270 N
radius = 1.20 m
The torque = F * r

However;
From the moment of inertia;

given that;
I = 84.4 kg.m²

For re-tardation; 
Using the equation



t = 0.398s
The required time it takes= 0.398s