Answer:
a) 20 m/s
b) 37.5 m)s
Explanation:
Average speed = total distance ÷ total time
=> (a) average speed of a car that travels 400m in 20s
= 400/20 = 20 m/s
& (b) average speed of an athlete who runs 1500m in 4 minutes (or 4×60=240 seconds)
= 1500/240 = 37.5 m/s
Answer:
t = 0.0735 m
Explanation:
Angular acceleration of the flywheel is given as

now after t = 8 s the speed of the flywheel is given as



now rotational kinetic energy of the wheel is given as




now we have



Answer:
0.687 m/s
Explanation:
Initial energy = final energy
1/2 mu² = mgh + 1/2 mv²
1/2 u² = gh + 1/2 v²
Given u = 2.00 m/s, g = 9.8 m/s², and h = 0.180 m:
1/2 (2.00 m/s)² = (9.8 m/s²) (0.180 m) + 1/2 v²
v = 0.687 m/s
Weight = (mass) x (gravity)
= 200 Newtons.
(About 44 pounds. You're very skinny.)
F=mg
if m doubled, F would double as well