A baby girl of mass 10kg runs at a speed of 2.0ms-1 . If her acceleration is 0.5ms-1 , calculate
(i) the force on her
(ii) the time taken by her to cover a distance of 50m
(i) Using the formula for force:
F = ma
where F is force, m is mass, and a is acceleration.
F = 10kg x 0.5ms^-2
F = 5 N (newtons)
Therefore, the force on the baby girl is 5 N.
(ii) Using the formula:
d = 1/2at^2 + vt
where d is distance, a is acceleration, t is time, and v is initial velocity.
50m = 1/2 (0.5ms^-2)t^2 + 2.0ms^-1 t
50m = 0.25t^2 + 2t
0.25t^2 + 2t - 50m = 0
Using the quadratic formula:
t = (-b ± √(b^2 - 4ac))/2a
where a = 0.25, b = 2, and c = -50.
t = (-2 ± √(2^2 - 4(0.25)(-50)))/2(0.25)
t = (-2 ± √(404))/0.5
t ≈ 14.48 s or t ≈ -3.48 s
Since time cannot be negative, the time taken by the baby girl to cover a distance of 50m is approximately 14.48 seconds.
1.
Ferns and pine trees can be classified as different organisms from each other based on whether they have
a nonvascular system.
a vascular system.
flowers.
seeds.
b) a vascular system.
An organism that makes its own food is called a(n)
eukaryote
autotroph
prokaryote
heterotroph
b) autotroph.
3.
Which is a characteristic that organisms in domain Eukarya share?
They lack cell structures and membranes.
They have cell structures without membranes.
They are multicellular.
They are unicellular.
c) They are multicellular.
What trait differentiates lilacs from pine trees?
Pine trees have leaves.
Pine trees produce seeds.
Lilacs are vascular plants.
Lilacs have flowers.
d) Lilacs have flowers.
Which characteristic is common among vertebrates?
eat with teeth
supported by an exoskeleton
make own food
breathe with lungs or gills