A parachute attains a terminal velocity when
its density is equal to the density of air
the viscous force of the air and the upthrust completely counteract its weight
it expands as a result of reduced external pressure
the viscous force of the air is equal to the sum of the weight and upthrust
Correct answer is B
No explanation has been provided for this answer.
1.8m
2.0m
2.5m
3.0m
Correct answer is D
Power x time = mgh
120 x 20 = 80 x 10 x h
2400 = 800h
making h the subject of formula,divide both side by 800
\(\frac{2400}{800}\) = h
h = 3m
1.1 x 10-5N
3.3 x 10-5N
3.0 x 10-4N
9.0 x 10-4N
Correct answer is D
F \(\alpha \frac{1}{r^2}\)
therefore, \(\frac{F_1}{F_2}\) = \(\frac{r_1}{(r_2)^2}\)
\(\frac{10^{-4}}{F_2}\) = \(\frac{(0.06)^2}{(0.18)^2}\)
F = 9 x 10-4N
3.0Ns
4.5Ns
7.5Ns
12.0Ns
Correct answer is D
Impulse = m(v-u)
= 0.15(50--30)
= 0.15 X 80
= 12N/s
5s
10s
12s
15s
Correct answer is A
In free fall, every object will reach the ground at same time