18, 19, and 20 are absurdly written questions, written by someone who is unclear on the concepts. These three questions have no logical answers, and are terribly misleading for students who are trying to learn this stuff.
I haven't had the guts to review the other 12 questions on the sheet. But really, the sheet should be shown to somebody in a higher position in the Science department of your school system. This kind of material should be unacceptable in an educational setting, except once a year, on April 1.
Answer: distance = 24 meters
Explanation:
speed = distance / time
distance = speed x time
speed = 160 cm/s = 1.6 m /s [ 100 cm = 1 m, 160 cm = 1.6 m ]
time = 15 s
distance = 1.6 m/s x 15 s = 24 m
Answer:
(a)
(b)
Explanation:
Given data
The angular velocity of two cylinders ω=257 rad/s
The mass of the two cylinders m=2.88 kg
The radius of small cylinder r₁=0.319 m
The radius of larger cylinder r₂=0.605 m
For Part (a)
The rotational kinetic energy of the cylinder is given by:
Where I is rotational of inertia of solid cylinder about its central axis.
So
Substitute the given values
So
For Part (b)
Substitute the given values
Explanation:
Equation for Impact
FΔt = ΔP,
F = force
Δt = Impact of time
ΔP = Change in momentum
Car steering is engineered to fail in order to maximize the time of contact and hence reduce the initial impact and mitigate the damage incurred.
Road guard railing crumple on contact to maximize impact time and hence reduce impact intensity and mitigate damage.
Road safety containers are loaded with liquid or sand as they improve the period of impact.