Explanation:
There's not enough information in the problem to solve it. We need to know either the initial speed of the lorry, or the time it takes to stop.
For example, if we assume the initial speed of the lorry is 25 m/s, then we can find the rate of deceleration:
v² = v₀² + 2aΔx
(0 m/s)² = (25 m/s)² + 2a (50 m)
a = -6.25 m/s²
We can then use Newton's second law to find the force:
F = ma
F = (7520 kg) (-6.25 m/s²)
F = -47000 N
Explanation:
weight of water displaced=weight of sphere,
Since, plastic sphere floats in water with 50.0% of its volume submerged
so, water=2 sphere,
so sphere's density = 1/2 of water's density
Now, weight of glycerin displaced=weight of sphere,
Also given This same sphere floats in glycerin with 40.0% of its volume submerged.
so glycerin =2.5 sphere,
so sphere's density = .4 of glycerin's = 1/2 of water's.
So glycerin = 1.25 water
Answer:
1.89*10^8 J
Explanation:
The coefficient of performance of this device is 
where Q .is the useful heat supplied or removed by the considered system and W is the work required by the considered system.
Step 1
Coeffiecient of perfromance for cooling (COPC) = 1.75 = .
Q = 1.75W
Step 2
We convert day into seconds:
1 day = 24 hrs = 86400 seconds
Step 3
Heat that can be extracted from the house in a day is:
Q = 1.75 * 1.25 * 10^3 * 86400 = 189000000 = 1.89*10^8 J
