Explanation:
The attached figure shows data for the cart speed, distance and time.
For low fan speed,
Distance, d = 500 cm
Time, t = 7.4 s
Average velocity,

Acceleration,

For medium fan speed,
Distance, d = 500 cm
Time, t = 6.4 s
Average velocity,

Acceleration,

For high fan speed,
Distance, d = 500 cm
Time, t = 5.6 s
Average velocity,

Acceleration,

Hence, this is the required solution.
Answer:
W =1562.53 N
Explanation:
It is given that,
Radius of the aluminium ball, r = 24 cm = 0.24 m
The density of Aluminium, 
We need to find the thrust and the force. The mass of the liquid displaced is given by :

V is volume
Weight of the displaced liquid
W = mg

So,

So, the thrust and the force is 1562.53 N.
Answer:
Explanation:
The efficiency of a refrigerator is defined in the terms of coefficient of performance (COP).
The ratio of amount of heat in cold reservoir to the work done is termed as the COP.
COP = QL / W
COP = T2 / (T1 - T2)
Where, T1 be the temperature of hot reservoir, T2 be the temperature of cold reservoir.