Answer:5m
Explanation:a=-10m/s (since it moved upwards against gravity)
V=0
U=10m/s
v2=u2+2as
0= 100-20s
20s=100
s=5m
Solution:
54 / 9 = 6 boxes.
charge needed= 169412 C
Explanation:
energy stored in the battery= 16 KWh= 16 (1000 W)(3600 s)= 5.76 x 10⁷ J
Energy stored is given by U= q V
q= charge
V= voltage= 340 V
so 5.76 x 10⁷ = q (340)
q= 169412 C
Answer : The number of half-life periods will be, 3
Explanation : Given,
Initial amount of lead = 10 kg
Amount of lead after decay = 1.25 kg
Half-life = 22 years
Formula used :

where,
a = amount of reactant left after n-half lives
= Initial amount of the reactant
n = number of half lives
= half-life
Now put all the given values in the above formula, we get:




Thus, the number of half-life periods will be, 3