This being a perfect collision means no energy is lost during the collision. Because this question asks for speed and not velocity, the speed will be the same because the final energy is the same. The speed after the collision would therefore be 1.27 m/s.
Answer: 2.7 x 10^5 joules
Explanation:
Given that:
Time taken = 3 minutes
convert time in minutes to seconds
(Since 1 minute = 60 seconds
3 minutes = 3 x 60 = 180 seconds)
Power of toaster = 1500 watt
Work done by the toaster = ?
Recall that power is the rate of work done per unit time
i.e Power = work/time
work = Power x Time
Work = 1500 watt x 180 seconds
Work = 270000J
Place the result in standard form
270000J = 2.7 x 10^5J
Thus, 2.7 x 10^5 joules of work is done by the toaster.
3.
a)
r = distance of each mass in each hand from center = 0.6 m
m = mass of each mass in each hand = 2 kg
v = linear speed = 1.1 m/s
L = combined angular momentum of the masses = ?
Combined angular momentum of the masses is given as
L = 2 m v r
L = 2 (2) (1.1) (0.6)
L = 2.64 kg m²/s
b)
v' = linear speed when she pulls her arms = ?
r' = distance of each mass from center after she pulls her arms = 0.15 m
Using conservation of momentum , angular momentum remains same, hence
L = 2 m v' r'
2.64 = 2 (2) (0.15) v'
v' = 4.4 m/s
